Weights and Measures Citation (Metrological Control of Water Meters) Regulations, 2014 (G.N. No. 451 of 2014)

Weights and Measures (Metrological Control o/Water Meters) GOVERNMENT NOTICE No. 451 published on 07/1112014 THE WEIGHTS AND MEASURES ACT (CAP. 340) REGULATIONS (Made under section 54) WEIGHTS AND MEASURES (METROLOGICAL CONTROL OF WATER METERS) REGULATIONS, 2014 PART I PRELIMINARY PROVISIONS 1. These Regulations may be cited as the Weights and Measures Citation (Metrological Control of Water Meters) Regulations, 2014. and 2. These Regulations shall apply to sales meters. 3. In these Regulations, unless the context otherwise requires: "Act" means the Weights and ¥easures Act; "Agency" means the Weights and Measures Agency; "agent" means a qualified independent organ or individual responsible for conducting re-verification of water meters; "assizer" means a Weights and Measures Officer appointed under section 14(2) of the Act; "certificate" means a document issued by an assizer to certify that a measuring instrument is in conformity with the prescribed requirements; "Commissioner" means the Commissioner for Weights and Measures appointed under section 14( I) of the Act; "community organisation" means a community owned water supply organisation established under section 31 of the Water Supply and Sanitation Act; commence ment Applica tion Interpre tation Cap. 340 Cap 273 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451(Contd) Cap. 273 "competent authority" means an organisation which has a mandate, sufficient skill, knowledge and ability to ascertain issues relating to metrological control of water meters; "consumer" means a water utility that uses a water meter to provide water to a client; "entity" means a corporate body authorised by a competent authority to provide water services in Mainland Tanzania; "examiner" means a competent re-verification institution or agent approved approved to conduct test and re-verification of a water meters; "individual person" means an independent person authorised by a competent authority to provide water services in Mainland Tanzania; "inspection" means a process of investigating the compliance of a water meter requirements and its installation; "inspection committee" means a technical committee established by the Commissioner under regulation 22; "OIML R 49-1 (2006)" means the document prescribing metrological and technical requirements for water meters intended for the metering of cold potable water and hot water published by the International Organisation of Legal Metrology; "old meter" means a sales meter in use or stocked before commencement of these Regulations; "re- verification" means the examination, testing, passing as fit for use for trade and stamping any weights, measures, or measuring instruments, carried out to water meter in use or already undergone verification but its validity has expired, in conformity with the requirements ofOIML R 49-1; "re-verification institution" means an autonomous public organisation responsible for conducting re-verification of water meters; "sales meter" means a water meter used by water utility for the settlement of the sale of water; "sampling method" means a process and a technique of obtaining a representative sample from a total population; "service provider" means a service provider appointed in accordance with sections 19 and 35 of the Water Supply and Sanitation Act; 2 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) "supplier" means a person or company that provides water meter to water utility; "tests" means an act of observing and inspecting a water meter and its installation; "total population" means group of water meters of which sampling may be drawn; "verification" means the examination, testing, passing as fit for use for trade and stamping any weights, measures, or measuring instruments, carried out to new water meter before put into use and repaired water meter, in conformity with the requirements ofOIML R 49-1; "water authority" means a water supply and sanitation authority established under section 9 of the Water Supply and Sanitation Cap. 273 Act; "water meter verification" means validation of a water meter by an assizer or a person authorized by the Commissioner; "water meter" means a measuring instrument intended to measure continuously, memorize and display the volume of water passing through the meter at metering conditions; and "water utility" means an entity such as water authority, community organization, service provider and individual person authorized to distribute water in a demarcated area. PART II V ERIFICATION OF WATER METERS 4. An assizer may allow the use of an old water meter which meets Old the requirements of accuracy and standard stipulated in the OIML R 49- meters 1 prescribed in the Third Schedule. 5.-( 1) A water meter shall, prior to its initial use, be subjected to Verification verification. (2)A supplier shall not supply any water meter which is not verified. (3) The supplier shall, when supplying water meter, in writing inform the consumer of the meter verification status. (4) The Agency may appoint an agent to conduct verification of water meter on its behalf. 3 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) Supplier of water meter Water utility Metrolo gical require ments Power to reject, return meter Verification procedures PART III RESPONSIBILITIES OF A SUPPLIER OF A WATER METER AND WATER UTILITY 6. A supplier of a measuring instrument shall not supply, sell or deliver water meter without prior approval by the Commissioner 7.-( 1) A water utility shall ensure that water meter for settlement of water consumption meets the requirements ofthese Regulations. (2) A water utility shall, when procuring or installing a water meter, comply with manufacturer's conditions concerning the use and permitted operating conditions for which the meters are manufactured and install a water meter which meets the Metrological and Technical Requirements ofOIML R 49-1 prescribed in the TJ!ird Schedule. PART IV METROLOGICAL REQUIREMENTS FOR WATER METER 8. Metrological requirements of a water meter shall be in conformity with the requirements provided in OIML R 49 -1 set out in the Third schedule. 9.-( 1) An assizer shall, in the course of inspecting and testing a water meter, reject such a meter where he finds that a particular water meter does not meet the requirements of these Regulations. (2) An assizer may, when satisfied that a water meter has reparable technical defect, return the meter to the owner for adjustment or repair. (3) Where the assizer rejects a water meter pursuant to sub regulation (1), he shall: (a) issue a rejection note in the prescribed form; (b) retain the meter for the purpose of instituting criminal proceedings; or (c) in case of irreparable water meter, issue a condemnation note in the prescribed form. PART V VERIFICATION PROCEDURES 10.- (1) The assizer or authorised agent shall, in verifying new meter or re-verifying old meter, use total popUlation. 4 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) (2) Re-verification of water meter shall be conducted in the year of the expiry of its validity. (3) The approval of internal control in lieu of re-verification shall be supported sampling method, and where a water meter is re-verified by sampling method, its approval shall indicate the sampling method adopted. 11. An assizer or examiner shall, while testing a meter ensure that: (a) the flow rate characteristics of a water meter are defined by the range of flow rate values; (b) the testing requirements abide to metrological, technical and test method requirements provided under the OIML R 49-1 set out in the Third Schedule; (c) manufacturers' instructions are adhered to relevant water pressure and other conditions for tests of water meters; (d) temperature and flow rate are in conformity with the provisions of these Regulations; (e) the minimum requirements of measured quantity in tests are sufficiently considering the uncertainty of measurements; (f) the transportation of a water meter to and from the testing laboratory to the place of use meet the requirements of the quality system for transport. 12. The installation of a water meter shall be in conformity with provisions of the OIML R 49-1 set out in the Third Schedule and manufacturers' installation standards and instructions. 13.-(1) The initial and subsequent verification of water meters shall be as follows: (a) during every second year after the day of first installation or verification process for mechanical cold water meter with nominal flow rate up to 2.5 m3/h; (b) during the third year after the day of first installation or verification process for mechanical cold water meters with nominal flow rate above 2.5 m3/h and higher; (c) during the third year after the day of first installation or verification process for mechanical hot water meters; and 5 Test Require ments Installa tion require ments Validity periods ofre verification Weights and Measures (Metrological Control a/Water Meters) GN. No. 451 (Contd) Grouping and sampling procedures (d) during the third year after the day of third installation or verification process for electronic water meter. (2) Where it is possible to show, by a sampling method for inspection, that water meter in use meet the requirements laid down for the meters, the validity period of meter group concerned shall be extended. (3) The first verification of meters in use which have not been (4) A water meter which has been adjusted or repaired, and whose seal has been broken, shall be re-verified prior to its use or re-use. 14.-(1) An assizer may classify a water meter with the following features into one group: (a) identical meters, which have the self-same type markings; and (b) meters manufactured in the same reference year or within the period of not earlier or later than eighteen months from reference year. (2) The manufacturing year of all meters in the group shall be within a period not exceeding three years and that the reference time of inspections shall be the middle of the period. (3) For the purposes of sub regulation (1), sampling method for inspections of water meter shall be conducted in accordance with the provisions of the First and Second Schedule. (3) During grouping, the reference for water meter that has been repaired shall be the date of verification instead of the installation date. (4) Sampling from a group shall be performed in such a manner that each individual water meter in the group has equal chance to be selected. (5) A random schedule or another mathematical model shall be used to ensure random selection. (6) Water meter shall not be added into a group after it has been approved for sampling method of inspection. (7) At least ten percent of additional meters shall be selected for sampling method which may be reserved as provided under First and Second Schedules. 6 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451(Contd) 15.-( 1) A water meter which is not in normal processing condition and ideal for grouping and which is selected for sampling method for inspection, shall not be tested with a view to exchanging it with a reserve meter. (2) A water meter may be removed from the sampling if it has any of the following defects: (a) it has been tampered with; (b) it is broken or damaged; (c) it does not belong to the same group; and (d) its user permission to dismount is not obtained at the appointed time. 16.-( 1) An assizer or agent shall use sampling method for inspections for a group having at least nine meters. (2) An assizer or agent shall, when conducting inspection, be guided by the provisions of inspection and quality limit prescribed in the First and Second Schedule respectively. PART VI INTERNAL CONTROL, RE-VERIFICATION, PARTIES AND TESTING LABORATORIES 17.-(1) A water utility shall, after obtaining the approval of the Commissioner, use internal control instead of re-verifications. (2) A water utility shall ensure that its internal control system is correct and is in conformity with provision of OIML R 49-1 prescribed in the Third Schedule. (3) Tests and sampling method for inspection of meters conducted by using internal control system shall be in accordance with the provisions of these Regulations. (4) Water utility shall, when using internal control system in lieu of re-verification, apply an information system which is subject to the scope of these Regulations. (5) Water utility shall document its internal control system in the water utility's control and quality manual. 18.- (1) A water utility may apply for approval and acceptance of the quality system and other formal arrangement of internal control system of water meters in lieu ofre-verification. 7 Use of reserve meters Sampling method Instructions Internal control system Application for internal control system Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) Annual SupetVision and Reporting (2) An application under sub-regulation (I) shall be made to the Commissioner in the prescribed form and supported by (a) a control and quality manual on the system for internal control based on OIML R 49.1 as may be applicable; (b) a water utility's contract with an accredited examiner on the pre- inspection of the pertaining internal control; (c) an overview of the operation of the system and other information which the Commissioner considers necessary for approval if such information is not revealed in the control and quality manual; and (d) an application fee. (3) The Commissioner shall, upon the receipt of an application under sub regulation (2) and before approving sLlch application, direct an accredited examiner to conduct a pre-inspection. (4) Where the Commissioner is satisfied that an application for approval of internal control system meets the requirements, he shall approve the use of internal control system in lieu of re-verification. (5) Where the Commissioner rejects the application, he shall, within fourteen days, notify the applicant and give reasons for rejection. (6) Where the internal control system approved under sub regulation (4) does no longer meets the conditions, the Commissioner shall withdraw the approval for internal control system of water meter. 19.-(1) a water utility which has obtained the approval of the commissioner for internal control system shall have a contract with an accredited examiner concerning annual supervision. (2) An accredited examiner shall render an annual re-verification report to the Commissioner not later than by 01 sl March in respect of the immediate past calendar year concerning all supervision and inspections, conclusions of inspections and decisions which have been made concerning meters. (3) The report referred to under sub regulation (2) shall contain a statistical survey of all types of break-downs, defects, errors and broken seals of meters, recorded information about incolTect connections, other deviations and water meters which have remained unchanged in its quality. 8 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451 (Contd) (4) The Commissioner shall confirm not later than 1 st June the extension of the time of validity of permission for internal control against payment of an annual supervisory fee. 20.- (1) An examiner employed by a water utility to undertake re- Examiner verifications of water meter shall be independent from water utility. (2) An examiner may apply to the Commissioner to grant a water utility which has no internal control system with are-verification approval. 21.- (I) Any testing laboratory for water meter shall be accredited by a competent authority and shall test water meter for a water utility in accordance with these Regulations. (2) A testing laboratory may be established and maintained by a water utility. PARTVIf SUPERVISION, MARKET SURVEILLANCE AND ADMINISTRATIVE RESORTS 22.- (1) The Commissioner may, for the purposes of discharging duties conferred to him under section 15 of the Act, establish an inspection committee. (2) The Inspection committee established under sub regulation (1) shall consist of not more than seven members and it shall advise the Commissioner on technical issues relating to the compliance of the provisions of these Regulations and undertakes market surveillance in conformity with OIML R 49-1 requirements set out in the Third Schedule. 23. The Agency shall collect a licensing fee and an annual supervisory charge on internal control at the rate prescribed in the Fee Regulations. PART VIII GENERAL PROVISIONS 24. Any person who is aggrieved by a decision made by the Commissioner in the exercise of the powers vested in him by these Regulations may, within fourteen days from the date of the decision, appeal to the Minister. 9 Testing laborato ries Inspection committee Cap. 340 Fees on internal control system GNNo. 444 of 2010 Appeal and means of complaints Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) Offences 25. Any person who contravenes the provisions of these Regulations commits an offence and shall be liable, on conviction, to a fine as provided under the Act. Transition 26.- (1) Any water meter which has been in use before coming into provisions force of these Regulations shall be deemed to be in use in accordance with the provisions of these Regulations. (2) The commissioner shall, within two years of coming into force of these Regulations, verify meters referred to under sub regulation (I), and may approve such meter if it passes the applicable test. SCHEDULES FIRST SCHEDULE SMALL GROUPS, SINGLE SAMPLING PLAN Group Size Sample Size Criteria Criteria Reserve Meters For For Acceptance Rejection 9 - 15 3 0 I I 16 - 25 5 0 I I 26 - 50 8 0 I I 51 - 90 13 I 2 2 91 - 150 20 I 2 2 10 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) SECOND SCHEDULE LARGER GROUPS, DOUBLE SAMPLING PLAN Total Number of Group size Sample Sample sample nonconforming meters* size Criteria for Criteria for Reserve size acceptance reiection Meters 151 til 1200 first 32 32 0 2 6 second 32 64 I 2 6 1201 til 3200 first 50 50 I 4 10 second 50 100 4 5 10 3201 til 10000 first 80 80 2 5 16 second 80 160 6 7 16 10001 til 35000 first 125 125 5 9 25 second 125 250 12 13 25 In the lines for "second" sample the number ofnonconfonning meters applies to the total sampling. THIRD SCHEDULE OlMLR49 WATER METERS INTENDED FOR THE METERING OF COLD POTABLE WATER AND HOT WATER PART I: METROLOG ICAL AND TECHNICAL REQUIREMENTS INTERNATIONAL OIML 49-1 RECOMMENDATION Edition 2006 (E) Water meters intended for the metering of cold potable water and hot water Part I: Metrological and technical requirements Compteurs d'eau destines allmesurage de j'eau potable froide et de j'eau chaude Partie I: Exigences metrologiques et techniques 1 1 Weights and Measures (Metrological Control o/Water Meters) GN. No. 451 (Contd) 12 ORGANISATION INTERNATIONALE DE METROLOGIE LEGALE INTERNATIONAL ORGANIZATION OF LEGAL METROLOGY Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) Contents Foreword ................................................................................................................................ 3 SCOPE ............................................................................................................................. 4 2 TERMINOLOGY ............................................................................................................. .4 2.1 Water meter and its constituents ................................................................................. .4 2.2 Metrological characteristics ....................................................................................... 6 2.3 Operating conditions ................................................................................................... 7 2.4 Test conditions ............................................................................................................... 8 2.5 Electronic and electrical equipment ............................................................................. 9 3 METROLOGICAL REQUIREMENTS .......................................................................... 11 3.1 Values ofQI, Q2, Q3 and Q4 ...................................................................................... 11 3.2 Accuracy class and maximum permissible error ......................................................... 11 3.3 Requirements for meters and ancillary devices ............................................................ 13 4 WATER METERS EQUIPPED WITH ELECTRONIC DEVICES ........................... 14 4. I General requ irements ................................................................................................. 14 4.2 Power supply ............................................................................................................ 15 4.3 Checking facilities .................................................................................................... 16 5 TECHNICAL REQUIREIVIENTS ............................................................................... 19 5.1 Materials and construction of water meters .................................................................. 19 5.2 Adjustment and correction ........................................................................................ 19 5.3 Installation conditions ............................................................................................... 19 5.4 Rated operating conditions ......................................................................................... 20 5.5 Pressure loss ............................................................................................................... 20 5.6 Marks and inscriptions ............................................................................................. 20 5.7 Indicating device ....................................................................................................... 21 5.8 Verification marks and protection devices ................................................................... 23 6 METROLOGICAL CONTROLS ................................................................................ 24 6.1 Reference conditions .................................................................................................. 24 6.2 Pattern approval ....................................................................................................... 24 6.3 Initial verification ....................................................................................................... 30 7 TEST METHOD AND TEST REPORT FORMAT .................................................... 30 7.1 Test method ............................................................................................................. 30 7.2 Test report format ..................................................................................................... 30 AnnexA Performance tests for water meters with clectl'Onic devices (Mandatory) ............... 31 Annex B Terms used to char'acterizc a water meter (Informative) ......................................... .42 Bibliography ......................................................................................................................... .44 13 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) Foreword The International Organization of Legal Metrology (OIML) is a worldwide, intergovernmental organization whose primary aim is to harmonize the regulations and metrological controls applied by the national metrological services, or related organizations, of its Member States. The main categories of OIML publications are: International Recommendations (OIML R), which are model regulations that establish the metrological characteristics required of certain measuring instruments and which specify methods and equipment for checking their conformity. OIML Member States shall implement these Recommendations to the greatest possible extent; International Documents (OIML D), which are informative in nature and which are intended to harmonize and improve work in the field of legal metrology; International Guides (OIML G), which are also informative in nature and which are intended to give guidelines for the application of certain requirements to legal metrology; and International Basic Publications (OIML B), which define the operating rules of the various OIML structures and systems. OIML Draft Recommendations, Documents and Guides are developed by Technical Committees or Subcommittees which comprise representatives from the Member States. Certain international and regional institutions also participate on a consultation basis. Cooperative agreements have been established between the OIML and certain institutions, such as ISO and the IEC, with the objective of avoiding contradictory requirements. Consequently, manufacturers and users of measuring instruments, test laboratories, etc. may simultaneously apply OIML publications and those of other institutions. International Recommendations, Documents, Guides and Basic Publications are published in English (E) and translated into French (F) and are subject to periodic revision. Additionally, the OIML publishes or participates in the publication of Vocabularies (OIML V) and periodically commissions legal metrology experts to write Expert Reports (OIML E). Expert Reports are intended to provide information and advice, and are written solely from the viewpoint of their author, without the involvement of a Technical Committee or Subcommittee, nor that of the CIML. Thus, they do not necessarily represent the views of the OIML. This publication -reference OIML R 49-1, edition 2006 (E) -was developed by the OIML Technical Subcommittee TC 8/SC 5 Water meters. It was approved for final publication by the International Committee of Legal Metrology in 2006 and will be submitted to the International Conference of Legal Metrology in 2008 for formal sanction. This Edition supersedes the previous edition ofDlML R 49-1 (Edition 2003) and replaces R 72 (Edition 1985) Hot water meters. It incorporates requirements for hot water meters and combination meters. OIML Publications may be downloaded from the OIML web site in the form of PDF files. Additional information on OIML Publications may be obtained from the Organization's headquarters: Bureau International de Metrologie Legale II, rue Turgot -75009 Paris -France Telephone: 33 (0)1 4878 1282 Fax: 33 (0) 142821727 E-mail: biml@oiml.org Internet: www.oiml.org 14 Weights and Measures (Metrological Control o/Water Meters) GN. No. 451(Contd) OIML R 49- I: 2006 Water meters intended for the metering of cold potable water and hot water Part 1: Metrological and technical requirements 1 SCOPE 1.1 This Recommendation applies to water meters used to meter the actual volume of cold potable water and hot water flowing through a fully charged, closed conduit. These water meters shall incorporate devices which indicate the integrated volume. 1.2 This Recommendation sets out the conditions with which the water meters shall comply to meet the requirements of the Services of Legal Metrology in countries where these instruments are subject to State controls. 1.3 This Recommendation also applies to water meters based on electrical or electronic principles, and to water meters based on mechanical principles incorporating electronic devices, used to meter the actual volume flow of hot water and cold potable water. It also applies to electronic ancillary devices. As a rule ancillary devices are optional. However, national or international regulations may make some ancillary devices mandatory in relation to the utilization of the water meter. 1.4 In addition to the metrological and technical requirements included in this Part I (R 49- I) the methods of examination and testing are included in Part 2 (R 49-2 [9]) and the Test Report Format is included in Part 3 (R 49-3 [I I)). 2 TERMINOLOGY Many of the definitions used in this Recommendation conform to the International Vocabulary of Basic and General Terms in Metrology (VIM) [I], the International Vocabulary of Terms in Legal Metrology (VIML) [2] and OIML International Document D I I [3]. For the purposes of this Recommendation, the definitions below shall apply. 2.1 Water meter and its constituents 2.1.1 Water meter Instrument intended to measure continuously, memorize and display the volume of water passing through the measurement transducer at metering conditions. Note l. A water meter includes at least a measurement transducer, a calculator (including adjustment or correction devices, if present) and an indicating device. These three devices may be in different housings. 2. A water meter may be a combination meter comprising one large meter, one small meter and a changeover device that, depending on the magnitude of the tlowrate passing through the meter, automatically directs the flow through either the small or large meter or both. Meter reading is obtained from two independent totalizers or one totalizer, which adds up the values from both water meters. 15 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) IML R 49-1 : 2006 2.1.2 Measurement transducer Part of the meter which transforms the flow or the volume of the water to be measured into signals which are passed to the calculator. It can be based on a mechanical, or an electrical, or an electronic principle. It may be autonomous or use an external power source. Note: For the purposes of this Recommendation, the measurement transducer includes the flow sensor or volume sensor. 2.1.3 Flow sensor or volume sensor Part of the water meter (such as a disc, piston, wheel, turbine element, electromagnetic coil, or other transducer) which senses the tlowrate or volume of water passing through the meter. 2.1.4 Calculator Part of the meter which receives the output signals from the transducer(s) and, possibly, from associated measuring instruments, transforms them and, if appropriate, stores the results in memory until they are used. In addition, the calculator may be capable of communicating both ways with ancillary devices. 2.1.5 Indicating device -, Part of the meter which displays the measurement results either continuously or on demand. Note: A printing device which provides an indication at the end of the measurement is not an indicating device. 2.1.6 Adjustment device Device incorporated in the meter, that only allows the error curve to be shifted generally parallel to itself, with a view to bringing errors (of indication) within the maximum permissible errors. 2.1.7 Correction device Device connected to or incorporated in the meter for automatically correcting the volume at metering conditions, by taking into account the tlowrate andlor the characteristics of the water to be measured (e.g. temperature and pressure) and the pre-established calibration curves. The characteristics ofthe water to be measured may either be measured using associated measuring instruments, or be stored in a memory in the instrument. 2.1.8 Ancillary device Device intended to perform a particular function, directly involved in elaborating, transmitting or displaying measurement results. The main ancillary devices are: (a) zero setting device; (b) price indicating device; (c) repeating indicating device; (d) printing device; (e) memory device; (t) tariff control device; (g) pre-setting device; and (h) self service device. Note: An ancillary device mayor may not be subject to legal metrological control according to national regulations. 16 Weights and Measures (Metrological Control of Water Meter~) GN. No. 45] (Contd) OIML R 49-1: 2006 2.1.9 Tariff control device Device that allocates measurement results into different registers depending on tariff or other criteria, each register having the possibility to be displayed individually. 2. J.1 0 Pre-setting device Device which permits the selection of the quantity to be measured and which automatically stops the flow of the water at the end of the measurement of the selected quantity. 2.1.11 Associated measuring instruments Instruments connected to the calculator, the correction device or the conversion device, for measuring certain quantities which are characteristic of water, with a view to making a correction and/or a conversion. 2.1.12 Meter for two constant partners Meter permanently installed and only used for deliveries from one supplier to one customer. 2.2 Metrologieal characteristics 2.2. I Actual volume, Va Total volume of water passing through the water meter, disregarding the time taken. This is the measurand. 2.2.2 Indicated volume, V, Volume of water indicated by the meter, corresponding to the actual volume. 2.2.3 Primary indication Indication (displayed, printed or memorized) which is subject to legal metrological control. 2.2.4 Error (of indication) Indicated volume minus the actual volume [adapted from VIM 5.20). 2.2.5 Relative error (of indication) Error (of indication) divided by the actual volume [adapted from VIM 3.12). 2.2.6 Maximum permissible error (mpe) Extreme values of the relative error (of indication) of a water meter permitted by this Recommendation [adapted from VIM 5.21). 2.2.7 Intrinsic error Error (of indication) of a water meter determined under reference conditions [adapted from VIM 5.24], 2.2.8 Initial intrinsic error Intrinsic error of a water meter as determined prior to all performance tests. 2.2.9 Fault Difference between the error (of indication) and the intrinsic error of a water meter [adapted from OIML D II). 17 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R 49-1: 2006 2.2.10 Significant fault Fault. the magnitude of which is greater than one half of the maximum permissible error in the upper flowrate zone [adapted from OIML D II). The following are not considered to be significant faults: faults arising from simultaneous and mutually independent causes in the water meter itself or in its checking facilities; and transitory faults being momentary variations in the indication which cannot be interpreted, memorized or transmitted as a measurement result. 2.2.11 Durability Capability of the water meter to maintain its performance characteristics over a period of use [adapted from OIML D I I]. 2.2.12 Metering conditions Conditions of the water, the volume of which is to be measured, at the point of measurement (example: temperature and pressure of the water). 2.2.13 First. element. of an indicating device Element which, in an indicating device comprising several elements, carries the graduated scale with the verification scale interval. 2.2.14 Verification scale interval Lowest value scale division of the first element of an Indicating device. 2.2.15 Resolution (of an indicating device) Smallest difference between indications of an indicating device that can be meaningfully distinguished [adapted from VIM 5.12]. Note: For a digital device, this is the change in the indication when the least significant digit changes by one step. 2.3 Operating conditions 2.3.1 Flowrate, Q Quotient of the actual volume of water passing through the water meter and the time taken for this volume to pass through the water meter. 2.3.2 Permanent t1owrate, Q, Highest tlowrate within the rated operating conditions, at which the water meter is required to operate in a satisfactory manner within the ma.ximum permissible error. Flowrate is expressed in m3/h or kLih in this Recommendation. 2.3.3 Overload flowrate, Q 4 Highest flowrate at which a water meter is required to operate, for a short period of time, within its maximum permissible error, whilst maintaining its metrological performance when it is subsequently operated within its rated operating conditions. 18 Weights and Measures (Metrological Control o/Water Meters) GN. No. 451 (Contd) OIML R 49-1 : 2006 2.3.4 Transitional flowrate. Q2 Flowrate which occurs between the permanent flowrate Q3, and the minimum flowrate QI, that divides the flowrate range into two zones, the upper flowrate zone and the lower flowrate zone, each characterized by its own maximum permissible error. 2.3.5 Minimum flowrate, Q, Lowest flowrate at which the water meter is required to operate within the maximum permissible error. 2.3.6 Combination meter changeover flowrate, Qx Change-over flowrate Qxl is when flow stops in the larger meter with decreasing flowrate. Change-over flowrate Qx2 is when flow starts in the larger meter with increasing flowrate. 2.3.7 Minimum and maximum admissible temperature (mAT and MAT) Minimum and maximum water temperatures that a water meter can withstand permanently, within its rated operating conditions, without deterioration of its metrological performance. mAT and MAT are respectively the lower and upper of the rated operating conditions (ROC). 2.3.8 Maximum admissible pressure (MAP) Maximum internal pressure that a water meter can withstand permanently, within its rated operating conditions, without deterioration of its metrological performance. 2.3.9 Working temperature, T" Average water temperature in the pipe measured upstream and downstream of the water meter. 2.3.10 Working pressure,P" Average water pressure in the pipe measured upstream and downstream of the water meter. 2.3.11 Pressure loss, p Pressure loss, at a given f1owrate, caused by the presence of the water meter in the pipeline. The maximum pressure loss can differ from the pressure loss at the permanent f10wrate Q3 and at the overload flowrate Q4' 2.4 Test conditions 2.4.1 Influence quantity Quantity that is not the measurand but which atfects the result of the measurement [VIM 2.7]. 2.4.2 Influence factor Influence quantity having a value within the rated operating conditions of the water, as specified in this recommendation. 2.4.3 Disturbance Influence quantity having a value within the limits specified in this recommendation, buti outside the specified rated operating conditions of the water meter. Note: An influence quantity is a disturbance iffor that influence quantity the rated operating conditions are not specified. 19 Weights and Measures (Metrological Control o/Water Meters) GN. No. 451 (Contd) OIML R 49-1: 2006 2.4.4 Rated operating conditions (ROC) Conditions of use giving the range of values of the influence factors, for which the errors (of indication) of the water meter are required to be within the maximum permissible errors [adapted from VIM 5.5]. 2.4.5 Reference conditions Set of reference values, or reference ranges of influence quantities, prescribed for testing the performance of a water meter, or for the intercomparison of the results of measurements [adapted from VIM 5.7]. 2.4.6 Limiting conditions Extreme conditions, including flowrate, temperature, pressure, humidity and electromagnetic interference, that a water meter is required to withstand without damage, and without degradation of its error (of indication), when it is subsequently operated within its rated operating conditions [adapted from VIM 5.6]. 2.4.7 Performance test Test intended to verify whether the water meter (equipment under test, EUT) is capable of accomplishing its intended functions. 2.4.8 Endurance test Test intended to verify whether the water meter is able to maintain its performance characteristics over a period of use. 2.5 Electronic and electrical equipment 2.5.1 Electronic device Device employing electronic sub-assemblies and performing a specific function. Electronic devices are usually manufactured as separate units and are capable of being tested independently. Note: Electronic devices, as defined above, may be complete meters or parts of meters, in particular such as those mentioned in 2.1.1 through 2.1.5 and 2.1.8. 2.5.2 Electronic sub-assembly Part of an electronic device, employing electronic components and having a recognizable function of its own. 2.5.3 Electronic component Smallest physical entity which uses electron or hole conduction in semi-conductors, gases, or in a vacuum. 2.5.4 Checking facility Facility incorporated in a water meter with electronic devices and which enables significant faults to be detected and acted upon. Note: The checking of a transmission device aims at verifying that all the information which is transmitted (and only that information) is fully received by the receiving equipment. 2.5.5 Automatic checking facility Checking facility operating without the intervention of an operator. 20 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451 (Contd) OIML R 49- 2006 2.5.6 Permanent automatic checking facility (type P) Automatic checking facility operating during the entire measurement operation. 2.5.7 Intermittent automatic checking facility (type I) Automatic checking facility operating at certain time intervals or per fixed number of measure men I cycles. 2.5.8 Non-automatic checking facility (type N) Checking facility which requires the intervention of an operator. 2.5.9 Power supply device Device which provides the electronic devices with the required electrical energy, using one or several sources ofAC or DC. 3 METROLOGICAL REQUIREMENTS 3.1 Values of Q" Ql' Qj and Q, 3.1.1 The t10wrate characteristics of a water meter shall be defined by the values of Qt, Q2, Q3, and Q4. Annex B describes these concepts and their relationship to the measurement performance of a water meter. 3.1.2 A water meter shall be designated by the numerical value of Q3 in m3/h or kLih and the ratio Q/Qr The value ofQ3 shall be chosen from the following list: I 1.6 2.5 4 6.3 10 16 25 40 63 100 160 250 400 630 I 000 I 600 2500 4000 6300 Where the Qj values are expressed in m3/h or kLih. The list may be extended to higher or lower values in the series. From the values given, for water meters connected for 20mm use, the value of Q3 shall be 4. From the values given, for water meters connected for 15mm use, the value of Q3 shall be 2.5 or 4. 3.1.4 The value of the ratio Q 3 / Q, shall be chosen from the following list: 10 12.5 16 20 25 31.5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 The list may be extended to higher values in the series. From the values given, for water meters connected for 15mm or 20mm use, the minimum value of Q/Q, shall be 200. Note·. The values in 3.1.3 and 3.1.4 are taken from the R5 and RIO lines of ISO 3: 1973 [4] respectively. The ratio Q! Q, shall be 1.6. 21 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49- 2006 3.1.6 The ratio Q/ Q 3 shall be 25. 3.2 Accuracy class and maximum permissible error Water meters shall be designed and manufactured such that their errors (of indication) do not exceed the maximum permissible errors as defined in 3.2.1 or 3.2.2 under rated operating conditions. These requirements shall be met durably. Water meters shall be designated as either accuracy class I or accuracy class 2, according to the requirements of 3.2.1 or 3.2.2. 3.2.1 Accuracy class I water meters The maximum permissible error for the upper tlowrate zone (Q,::;; Q ::;; Q) is: ± I %, for temperatures from e O. I DC to 30°C, and: ± 2 % for temperatures greater than 30 DC. The maximum permissible error for the lower flowrate zone (QJ ::;; Q < Q) is ± 3 %. Accuracy class I designation shall be applied only to water meters with Q 3 :2: 100 m'/h or kLlh. 3.2.2 Accuracy class 2 water meters The maximum permissible error for the upper flowrate zone (Q, ::;; Q ::;; Q) is ± 2 %, for temperatures from 0.1 DC to 30 DC, and:f: 3 % for temperatures greater than 30 "c. The maximum permissible error for the lower flowrate zone (QJ ::;; Q < Q) is ± 5 %. Accuracy class 2 designation shall be applied to all water meters with Q3 < 100 m'/h or kLlh and may be applied to water meters with values of Q 3 :2: 100 m'/h or kLlh. 3.2.3 Meter temperature classes The meters form water temperature classes corresponding to the various ranges, chosen by the manufacturer from the values given in Table I. The water temperature shall be measured at the inlet of the meter. Table I -Meter temperature classes Class mAT (DC) MAT(°C) Reference condition (0C) T30 0.1 30 20 T50 0.1 50 20 T70 0.1 70 20 and 50 T90 0.1 90 20 and 50 T130 0.1 130 20 and 50 T180 0.1 180 20 and 50 D070 30 70 50 DO/90 30 90 50 DOll30 30 130 50 T301180 30 180 50 22 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R 49- I: 2006 3.2.4 Water meters with separable calculator and measurement transducer The calculator (including indicating device) and the measurement transducer (including flow sensor or volume sensor) of a water meter, where they are separable and interchangeable with other calculators and measurement transducers of the same or different designs, may be the subject of separate pattern approvals. The maximum permissible errors of the combined indicating device and measurement transducer shall not exceed the values given in 3.2.1 or 3.2.2 according to the accuracy class of the meter. 3.2.5 The relative error (of indication) is expressed as a percentage, and is equal to: (11; -VJ x 100 Va 3.2.6 The manufacturer shall specify whether or not the water meter is designed to measure reverse flow. If a meter is designed to measure reverse flow, the actual volume passed during reverse flow shall either be subtracted from the indicated volume or the meter shall record it separately. The maximum permissible error 00.2.1 or 3.2.2 shall be met bothjor forward and reverse flow. If a meter is not designed to measure reverse flow, the meter shall either prevent reverse llow, or it shall withstand accidental reverse flow without deterioration or change in its metrological properties jor forward flow. 3.2.7 The requirements relating to the maximum permissible errors shall be met for all temperature and pressure variations occurring within the rated operating conditions of the water meter. 'he water meter totalization shall not change when the flowrate is zero. 3.2.9 The maximum permissible err.ors ofa water meter while in service shall be twice the maximum permissible errors given in 3.2.1 or 3.2.2 according to the accuracy class of the meter. 3.3 Requirements for meters and ancillary devices 3.3.1 Connections between electronic parts The connections between the measurement transducer, the calculator and the indicating device shall be reliable and durable in accordance with 4.1.3 and 4.3.2. These provisions shall also apply to connections between the primary and secondary devices of electromagnetic meters. Note: Definitions of primary and secondary devices of electromagnetic meters are given in ISO 4006 [5]. 3.3.2 Adjustment device Meters may be provided with an electronic adjustment device, which may replace a mechanical adjustment device. 3.3.3 Correction device Meters may be fitted with correction devices; such devices are always considered as an integral part of the meter. The whole of the requirements which apply to the meter, in particular the maximum permissible errors specified in 3.2, are therefore applicable to the corrected volume at metering conditions. In normal operation, non-corrected volume shall not be displayed. The aim of a correction device is to reduce the errors (of indication) to as close to zero as possible Water meters with correction devices shall satify the performance tests of A.6. 23 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R 49- I: 2006 All the parameters which are not measured and which are necessary for correcting shall be contained in the calculator at the beginning of the measurement operation. The pattern approval certificate may prescribe the possibility of checking parameters which are necessary for correctness at the time of verification of the correction device. The correction device shall not allow the correction of a pre-estimated drift, for example in relation to time or volume. Associated measuring instruments, if any, shall comply with the applicable International Standards or Recommendations. Their accuracy shall be good enough to permit the requirements on the meter to be met, as specified in 3.2. Associated measuring instruments shall be fitted with checking devices, as specified in 4.3.6. Correction devices shall not be used for adjusting the errors (of indication) of a water meter to values other than as close as practical to zero, even when these values are within the maximum permissible errors. Calculator All parameters necessary for the elaboration of indications that are subject to legal metrological control, such as a calculation table or correction polynomial, shall be present in the calculator at the beginning of the measurement operation. The calculator may be provided with interfaces permitting the coupling of peripheral equipment. When these interfaces are used, the water meter's hardware and software shall continue to function correctly and its metrological functions shall not be capable of being affected. 3.3.5 Electronic indicating device The continuous display of volume during the period of measurement is not mandatory. However, interruption of the display shall not interrupt the action of checking facilities, if present. 3.3.5 Ancillary devices The relevant requirements of OIML R.I) 7 [6] shall be applied when the water meter is equipped with any of the following devices: • zero-setting device; • price indicating device; • printing device; • memory device; • pre-setting device; and • self-service device. 4 WATER METERS EQUIPPED WITH ELECTRONIC DEVICES 4.1 General requirements 4. 1.1 Water meters with electronic devices shall be designed and manufactured in such a way that significant faults do not occur when they are exposed to the disturbances specified in A.6. These requirements shall be met durably. 4.1.2 Water meters with electronic deyices shall be provided with the checking facilities specified in 4.3, except in the case ofnon-resettable measurements between two constant partners. Checking facilities are required only where the delivered volume of water is prepaid by the customer and cannot be confirmed by the supplier. All water meters equipped with checking facilities shall prevent or detect reverse flow, as specified in 3.2.6. 24 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451 (Contd) OIML R 49-1: 2006 4.1.3 Water meters equipped with checking facilities are presumed to comply with the requirements in 3.2 and 4.1.1 if they pass the design inspection and performance tests specified in 6.2.12.1 and 6.2.12.2. 4.1.4 Water meters not equipped with checking facilities are presumed to comply with the requirements in 3.2 and 4.1.1 if they pass the design inspection and performance tests specified in 6.2.12.1 and 6.2.12.2 in the following conditions: • five identical meters are submitted at pattern approval; • at least one of these five meters is submitted to the whole set of tests; and • no meter fails any test. 4.1.5 The meter shall also provide visual checking ofthe entire display which shall have the following sequence: • displaying all the elements (e.g. an "eights" test); and • blanking all the elements (a "blanks" test). Each step of the sequence shall last at least one second. 4.2 Power supply Three different kinds of basic power supplies for water meters with electronic devices are covered by this Recommendation: • external power supply; • non-replaceable battery; and • replaceable battery. These three types of power supplies may be used alone or in combination. The requirements for each type of power supply are covered by the following paragraphs. 4.2.1 External power supply 4.2.1.1 Water meters with electronic devices shall be designed such that in the event of an external power supply failure (AC or DC), the meter indication of volume just before failure is not lost, and remains accessible for a minimum of one year. The corresponding memorization shall occur at least either once per day or for every volume equivalent to 10 minutes offlow at Q ... 4.2.1.2 Any other properties or parameters ofthe meter shall not be affected by an interruption of the electrical supply. Note: Compliance with this clause will not necessarily ensure that the water meter will continue to register the volume consumed during a power supply failure. 4.2.3 The power supply shall be capable of being secured from tampering. 4.2.2 Non-replaceable battery The manufacturer shall ensure that the indicated I ifetime of the battery guarantees that the meter functions correctly for at least one year longer than the operational lifetime of the meter. Note: It is anticipated that a combination of a specified mmdmul11 allowable total volume registered, volume, displayed volume, indicated operational lifetime, remote reading and extreme temperatures will be considered when specifying a battery and during pattern approval. 25 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451 (Contd) OIML R 49-9 : 2006 4.23 RP a:etletE:tery 4.231 WaBtreee::tria:f JXMS" awy i sarep a:etletE:tey, tremnta:iLrEr s-al gveptri ~rUESfcr trerepa:ara1 d tretE:tey 4.232ll"erepa:ara1 died tretE:tery s-all:ei rdcaa:l O1trentte-. 4.233ll"ep:q:atiES at:! p:ran:tes d tre ntte- s-a I rd l:ecffe:ia:ll:~ttre i rtErl1.Pi01 d treele::tri a:f awywmtt-etE:tery isrepa:m. Note: It is anticipated that a combination of maximum allowable volume, displayed volume, remote reading and extreme temperatures will be considered when specifying a battery and during pattern approval. 4.2.3.4 The operation of replacing the battery shall be carried out in such a way which does not necessitate breaking the seal required for statutory metrological inspections. 4.2.3.5 The battery compartment shall be capable of being secured from tampering. 4.3 Checking facilities. 4.3. I Action of checking facilities The detection by the checking facilities of significant faults shall result in the following actions, according to the type: For checking facilities of type P or I: • automatic correction of the fault; or • stopping only the faulty device when the water meter without that device continues to comply with the regulations; or .. a visible or audible alarm; this alarm shall continue until the cause of the alarm is suppressed. In addition, when the water meter transmits data to peripheral equipment, the transmission shall be accompanied by a message indicating the presence of a fault. (This requirement is not applicable to the application of disturbances specified in A. 6). The instrument may also be provided with devices to estimate the volume of water having passed through the installation during the occurrence of the fault. The result of this estimate shall not be capable of being mistaken for a valid indication. The visible or audible alarm is not allowed in the case of two constant partners, non-resettable and non-prepaid measurements, where checking facilities are used, unless this alarm is transferred to a remote station. Note: The transmission of the alarm and repeated measured values from the meter to the remote station need not be secured if the measured values are repeated at that station. 4.3.2 Checking facilities for the measurement transducer The objective of these checking facilities is to verifY the presence of the measurement transducer, its correct operation and the correctness of data transmission. The verification of correct operation includes detection or prevention of reverse flow. However, it is not necessary for the detection or prevention of reverse flow to be operated electronically. 4.3.2.) When the signals generated by the flow sensor are in the form of pulses, each pulse representing an elementary volume, the pulse generation, transmission and counting shall fulfill the following tasks: • correct counting of pulse; 26 Weights and Measures (Metrological Control of Water Meters) GN. No. 45 J (Contd) OIML R49-l: 2006 • detection of reverse flow, if necessary; and • checking of correct function. This may be done by means of: • .three-pulse system with use of either pulse edges or pulse status; • double-pulse line system with use of pulse edges plus pulse status; and • double-pulse system with positive and negative pulses depending on the flow direction. These checking facilities shall be of type P. It shall be possible during pattern approval to verifY that these checking facilities function correctly • by disconnecting the transducer; or • by interrupting one of the sensor's pulse generators; or • by interrupting the electrical supply of the transducer. 4.3.2.2 For electromagnetic meters only, where the amplitude of the signals generated by the measurement transducer is proportional to the flowrate, the following procedure may be used: A simulated signal with a shape similar to that of the measurement signal is fed into the input ofthe secondary device, representing a flowrate between the minimum and maximum flowrates of the meter. The checking facility shall check the primary and the secondary device. The equivalent digital value is checked to verify that it is within predetermined limits given by the manufacturer and consistent with the maximum permissible errors. This checking facility shall be of type P or I. For type I facilities, checking shall occur at least every five minutes. Note: Following this procedure, additional checking facilities (more than two electrodes, double signal transmission, etc.) are not required. 4.3.2.3 The maximum permissible cable length between primary and secondary devices of an electromagnetic meter, as defined in ISO 6817: 1992 [7], shall be not more than 100 metres or not more than the value L expressed in metres according to the following formula, whichever is smaller: L = (k x c) I (fx C) where k=2x1Q5m c isttea:nidivity d tteooer, in 81m f is the field frequency during the measuring cycle, in Hz; and C is the effective cable capacitance per metre, in F/m. Note: It is not necessary to fulfill these requirements if the manufacturer's solutions ensure equivalent results. 4.3.2.4 For other technologies, checking facilities providing equivalent levels of security remain to be developed. 4.3.3 Checking facilities for the calculator The objective of these checking facilities is to verify that the calculator system functions correctly and to ensure the validity of the calculations made. No special means are required for indicating that these checking facilities function correctly. 4.3.3.1 the checking facilities for the functioning of the calculation system shall be type p or I. for type 1 the checking must occur at least either once per day or for every volume equivalent to 10 minutes of flow at QJ 27 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49 - I : 2006 The objective of this checking facility is to verify that: (a) the values of all permanently memorized instructions and data are correct, by such means as: • summing up all instruction and data codes and comparing the sum with a fixed value; • line and column parity bits (longitudinal redundancy check and vertical redundancy check); • cyclic redundancy check (CRC 16); • double independent storage of data; and • .storage of data in "safe coding", for example protected by checksum, line and column parity bits. (b) all procedures of internal transfer and storage of data relevant to the measurement result are performed correctly, by such means as: • write-read routine; • conversion and re-conversion of codes; • . use of "safe coding" (checksum, parity bit); and • double storage. 4.3.3.2 The checking facilities for the validity of calculations shall be of type P or I. For type I the checking must either occur at least once per day, or for every volume equivalent to 10 minutes of flow at Q3' This consists of checking the correct value of all data related to the measurement whenever these data are internally stored or transmitted to peripheral equipment through an interface. This check may be carried out by such means as parity bit, check sum or double storage. In addition, the calculation system shall be provided with a means of controlling the continuity of the calculation program. 4.3.4 Checking facility for the indicating device The objective of this checking facility is to verify that the primary indications are displayed and that they correspond to the data provided by the calculator. In addition, it aims at verifying the presence of the indicating devices when they are removable. These checking facilities shall either have the form as defined in 4.3.4.1 or that as defined in 4.3.4.2. 4.3.4.1 The checking facility of the indicating device is of type P; however, it may be of type I if a primary indication is provided by another device. Means may include, for example: • for indicating devices using incandescent filaments or light emitting diodes, measuring the current in the filaments; • for indicating devices using fluorescent tubes, measuring the grid voltage; and • for indicating devices using multiplexed liquid crystals, output checking of the control voltage of segment lines and of common electrodes, so as to detect any disconnection or short circuit between control circuits. The checks mentioned in 4.1.5 are not necessary. 4.3.4.2 The checking facility for the indicating device shall include type P or type I checking of the electronic circuits used for the indicating device (except the driving circuits of the display itself); this checking facility shall meet the requirements of 4.3.3.2. 4.3.4.3 It shall be possible during pattern approval to determine that the checking facility of the indicating device is working, either: • by disconnecting all or part of the indicating device; or • by an action which simulates a failure in the display, such as using a test button. Checking facilities for ancillary devices 28 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49- I : 2006 An ancillary device (repeating device, printing device, memory device, etc.) with primary indications shall include a checking facility of type P or I. The aim of this checking facility is to verify the presence of the ancillary device, when it is a necessary device, and to verify correct functioning and correct transmission. 4.3.6 Checking facilities for the associated measuring instruments Associated measuring instruments shall include a checking facility of type P or I. The aim of this checking facility is to ensure that the signal given by these associated instruments is inside a predetermined measuring range. Examples: • four wire transmission for resistance type temperature sensors; and • control of the driving current for 4-20 mA pressure sensors. 5. TECHNICAL REQUIREMENTS 5.1 Materials und construction of wutcr mcters 5.1.1 The water meter shall be manufactured from materials of adequate strength and durability for the purpose for which the water meter is to be used. 5.1.2 The water meter shall be manufactured from materials which shall not be adversely affected by the water temperature variations, within the working temperature range (see 5.4). 5.1.3 All parts of the water meter in contact with the water flowing through it shall be manufactured from materials which are conventionally known to be non-toxic, non-contaminating and biologically inert<!). 4 The complete water meter shall be manufactured from materials which are resistant to internal external corrosion, or which are protected by a suitable surface treatment. 5.1.5 The water meter indicating device shall be protected by a transparent window. A cover of a suitable type may also be provided as additional protection. 5.1.6 The water meter shall incorporate devices tor elimination of condensation, where there is a risk of condensation forming on the underside of the window of the water meter indicating device. 5.2 5.2. Adjustment und concction 5.2.1 The water meter may be titted with an adjustment device, and/or a correction device. 5.2.2 If these devices are mounted on the outside of the water meter, provision for sealing shall be made (see 5.8.2). 5.3 Installation conditions(2) 5.3.1 A water meter shall be installed such that it is completely filled with water under normal conditions. 5.3.2 If the accuracy of the water meter is likely to be affected by the presence of solid particles in the water (turbine and displacement type water meters, for example), it shall be provided with a strainer or filter, fitted at its inlet or in the upstream pipeline(3) (I) National regulations shall apply, (1) See International Document OIML 0 .. /1f.\'tallafirJlJ ami ,\'forage comilliolls/Of cold water melerj' 18J. 29 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49-1: 2006 5.3.3 Provision may be made on the water meter to allow the water meter to be correctly leveled during installation(4). 5.3.4 If the accuracy of the water meter is likely to be affected by disturbances in the upstream or downstream pipeline (for example due to the presence of bends, valves or pumps), the water meter shall be provided with a sufficient number of straight pipe lengths, with or without a flow straightener, as specified by the manufacturer, so that the indications of the installed water meter meet the requirements of3.2.1 or 3.2.2 with respect to the maximum permissible errors and according to the accuracy class of the meter. 5.4 Rated operating conditions The rated operating conditions for a water meter shall be as follows: Flowrate range: Ambient temperature range: Water temperature range: Ambient relative humidity range: Working pressure range: 5.5 Pressure loss Q{to Q 3 inclusive; + 5 °C to + 55 DC; Refer to Table I -Meter temperature classes -clause 3.2.3; 0% to 100 %, except for remote indicating devices where the range shall be 0 % to 93 %; 0.03 MPa (0.3 bar)(S) to at least 1.4 MPa (lObar), except for meters of diameter - 500 mm, where the maximum admissible pressure (MAP) shall be at least 0.6 MPa (6 bar). The pressure loss through the water meter, including its filter where the latter forms an integral part of the water meter, shall not be greater than 0.063 MPa (0.63 barfS) between QI and Q3' Meters with dual check valves may be tested for pressure loss without such devices being fitted. Note :The maximnm pressure loss can differ from, and may exceed, the pressure loss at the permanent flowrate Q3' 5.6 Marks and inscriptions The water meter shall be clearly and indelibly marked with the following information, either grouped or distributed on the casing, the indicating device dial, an identification plate, or on the meter cover if it is not detachable. Note; In the case of a combination meter, the markings below refer to the combination meter. (a) Unit of measurement: cubic metre or kilolitre (see 5.7.1.2); (b) Accuracy class, where it differs from accuracy class 2; (c) Numerical value ofQJ' and the ratio Q,/Q; The marking of the ratio Q/Q. is optional; (d) Pattern approval sign according to national regulations; (e) Name or trademark of the manufacturer; (f) Serial number (as near as possible to the indicating device). The marking of the year of manufacture is optional; (g) Direction of flow (shown on both sides of the body; or on one side only provided the direction of flow arrow will be easily visible under all circumstances); (h) Maximum admissible pressure (MAP) if it exceeds 1.4 MPa (14 barf),6). (1) Installation engineers should note that solid particles will collect in the water meter, for example, following work on the pipework upstream from the meter. (4) This can be a flat vertical or horizontal surface against which a temporary, or permanent, level indicating device e.g. spirit level, can be placed. (5) The unit bar may be used where national regulations permit. (6) The unit bar may be used where national regulations permit 30 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R 49-1 : 2006 (i) Letter V or H, if the meter can only be operated in the vertical or horizontal position; U) The temperature class as specified in table I where it differs from no; and (k) The manufacturer may indicate the maximum pressure loss. For water meters with electronic devices, the following additional inscriptions shall be applied where appropriate: (I) For an external power supply: the voltage and frequency; (m)For a replaceable battery: the latest date that the battery is to be replaced; and (n) For a non-replaceable battery: the latest date by which the meter is to be replaced. 5.7 Indicating device 5.7.1 General requirements 5.7.1.1 Function The indicating device of the water meter shall provide an easily read, reliable and unambiguous visual indication of the indicated volume. A combination meter may have two indicating devices, the sum of which provides the indicated volume. The indicating device shall include visual means for testing and calibration. The indicating device may include additional elements for testing and calibration by other methods, e.g. for automatic testing and calibration. 5.7.1.2 Unit of measurement, symbol and its placement The indicated volume of water shall be expressed in cubic metres or kilolitres. The symbol m3 or kL shall appear on the dial or immediately adjacent to the numbered display. 5.7.1.3 Indicating range The indicating device shall be able to record the indicated volume in cubic metres or kilolitres corresponding to at least I 600 hours (rounded value) of operation at the permanent flowrate Q3. without passing through zero. This provision is formulated in Table 2. Table 2 Indicating range of a water meter Q3 mJ/h or kl/h Indicating range (minimum values) mJ or kl QJ :s; 6.3 9999 6.3<QJ < 63 99999 63<Q, < 630 999999 630<Q, < 6 300 9999999 5.7.1.4 Color coding for indicating devices. The colour black should be used to indicate the cubic metre or kilo I itre and its multiples. The colour red should be used to indicate sub-multiples of a cubic metre or kilolitre. These colours shall be applied to either pointers, indexes, numbers, wheels. discs. dials or to the aperture frames 31 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R 49-1:2006 Other means of indicating the cubic metre or kilolitre, its multiples and its sub-multiples may be used for electronic water meters, provided there is no ambiguity in distinguishing between the primary indication and alternative displays, e.g. sub-multiples for verification and testing. 5.7.2 Types of indicating device Any of the following types shall be used. 5.7.2. I Type 1 -Analog device The indicated volume is indicated by continuous movement of: (a) one or more pointers moving relative to graduated scales; (b) one or more circular scales or drums each passing an index. The value expressed in cubic metres or kilolitres for each scale division shall be of the form IOn, where n is a positive or negative whole number or zero, thereby establishing a system of consecutive decades. Each scale shall either be graduated in values expressed in cubic metres or kilolitres or accompanied by a multiplying factor (xO.OOI; xO.Ol; x O.I;xl; x 10; x 100; xl 000, etc.). Rotational movement of the pointers or circular scales shall be clockwise. Linear movement of pointers or scales shall be left to right. Movement of numbered roller indicators (drums) shall be upwards. 5.7.2.2 Type 2 -Digital device The indicated volume shall be given by a line of adjacent digits appearing in one or more apertures. These digits may be shown from a mechanical or electronic display. The advance of a given digit shall be completed while the digit of the next immediately lower decade changes from 9 to O. Movement of numbered roller indicators (drums) shall be upwards. The lowest value decade may have a continuous movement, the aperture being large enough to permit a digit to be read unambiguously. The apparent height of the digits shall be at least 4 mm. 5.7.2 .. 3 Type 3 -Combination of analog and digital devices The indicated volume is given by a combination of type I and type 2 devices and the respective requirements of each shall apply. 5.7.3 Supplementary devices In addition to the indicating devices already described in 5.7.1 and 5.7.2, the water meter may include supplementary devices which may be permanently incorporated or added temporarily. The device may be used to detect movement of the flow sensor before this is clearly visible on the indicating device. Where national regulations permit, the device may be used for testing and verification and for remote reading of the water meter, provided that other means guarantee the satisfactory operation of the water meter. 5.7.4 Verification devices -First element of an indicating device -Verification scale interval 5.7.4.1 General requirements Every indicating device shall provide means for visual, non-ambiguous verification testing and calibration. The visual verification display may have either a continuous or a discontinuous movement. 32 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) JIML R 49-1 :2006 In addition to the visual verification display, an indicating device may include provisions for rapid testing by the inclusion of complementary elements (e.g. star wheels or discs), providing signals through externally attached sensors. 5.7.4.2 Visual verification displays 5.7.4.2.1 Value of the verification scale interval The value of the verification scale interval expressed in cubic metres or kilolitres shall be of the form: 1 x 10", or 2 x IOn or 5 x 10", where n is a positive or negative whole number, or zero. For analog and digital indicating devices with continuous movement of the first element, the verification scale may be formed from the division into 2,5 or 10 equal parts of the interval between two consecutive digits of the first element. Numbering shall not be applied to these divisions. For digital indicating devices with discontinuous movement of the first element, the verification scale interval is the interval between two consecutive digits or incremental movements of the first element. 5.7.4.2.2 Form of the verification scale On indicating devices with continuous movement of the first element, the apparent scale spacing shall not be less than 1 mm and not more than 5 mm. The scale shall consist of: • either lines of equal thickness not exceeding one-quarter of the scale spacing and differing only in length; or • contrasting bands of a constant width equal to the scale spacing. The apparent width of the pointer at its tip shall not exceed one-quarter of the scale spacing and in no case shall it be greater than 0.5 mm. 5.7.4.2.3 Resolution of the indicating device The sub-divisions of the verification scale shall be small enough to ensure that the resolution error of the indicating device does not exceed 0.25 % for accuracy class I meters, and 0.5 % for accuracy class 2 meters, of the actual volume passed during I hour 30 minutes at the minimum flowrate Qr Additional verification elements may be used provided that the uncertainty of reading is not greater than 0.25 % of the test volume for accuracy class I meters and 0.5 % of the test volume for accuracy class 2 meters and that the correct functioning of the register is checked. Note: When the display of the first element is continuous, an allowance shall be made for a maximum error in each reading of not more than half the verification scale interval. When the display of the first element is discontinuous, an allowance shall be made for a maximum error in each reading of not more than one digit of the verification scale. 5.7.4.2.4 Combination meters For combination meters with two indicating devices, clauses 5.7.4.1, 5.7.4.2 apply to both indicating devices. 5.8 Verification marks and protection devices 5.8.1 A place shall be provided on water meters for affixing the main verification mark, which shall be visible without dismantling the water meter. S.S.2 Water meters shall include protection devices which can be sealed so as to prevent, both before and after correct installation of the water meter, dismantling or modification of the meter, its adjustment device or its correction device, without damaging these devices. In the case of combination meters, this requirement applies to both meters. 5.8.3 Electronic sealing devices 33 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49- 1:2006 5.8.3.1 When access to parameters that influence the determination of the results of measurements is not protected by mechanical sealing devices, the protection shall fulfill the following provisions: (a) Access shall only be allowed to authorized people, e.g. by means of a code (key-word) or ofa special device (e.g. a hard key). The code shall be capable of being changed; and (b) It shall be possible for at least the last intervention to be memorized. The record shall include the date and a characteristic element identifYing the authorized person making the intervention (see (a) above). The traceability of the last intervention shall be assured for at least two years, if it is not overwritten on the occasion of a further intervention. If it is possible to memorize more than one intervention and if deletion of a previous intervention must occur to permit a new record, the oldest record shall be deleted. 5.8.3.2 For meters with parts which may be disconnected one from another by the user and which are inter changeable, the following provisions shall be fulfilled: (a) It shall not be possible to access parameters that participate in the determination of results of measurements through disconnected points unless the provisions in 5.8.3.1 are fulfilled; and (b) Interposing any device which may influence the accuracy shall be prevented by means of electronic and data processing securities or, if this is not possible, by mechanical means. 5.8.3.3 For meters with parts which may be disconnected one from another by the user and which are not interchangeable, the provisions in 5.8.3.2 shall apply. Moreover, these meters shall be provided with devices which do not allow them to operate if the various parts are not connected according to the manufacturer's configuration. Note: Disconnections which are not allowed to the user may be prevented, for example, by means of a device that prevents any measurement after disconnecting and reconnecting. 6. METROLOGICAL CONTROLS 6.1 Reference conditions All influence quantities, except for the influence quantity being tested, shall be held to the following values during pattern evaluation tests on a water meter: Flowrate: 0.7 x (Q2 + Q) ± 0.03 x (Q2 + Q); Water temperature: Within ± 5 "C of reference value(s) of Table I; Ambient temperature: (20 ± 5) DC; Ambient relative humidity: (60 ± 15) %; Ambient atmospheric pressure: 86 kPa to 106 kPa [0.86 to 1.06 bar). 6.2 Pattern approval 6.2.1 Before undergoing pattern evaluation tests, each pattern of water meter submitted shall be examined externally to ensure that it complies with the provisions ofthe relevant preceding clauses of this Recommendation. 6.2.2 The evaluation tests shall be made on the minimum number of samples of each pattern shown in Table 3 as a function of the water meter designation Q3 of the pattern presented. The service responsible for pattern evaluation may request further specimens. 34 Weights and Measures (Metrological Control a/Water Meters) GN. No. 45 J (Contd) OIML R 49- 1 :2006 Table 3 Number of water meters to be tested Meter designation Q, (m3/h or kLlh) Minimum number of meters Q] S; 160 3 160<Q] S; 1600 2 1600 S; Q] 1 Note: Additional samples are required for meters equipped with electronic devices (see 4.1.4). The requirements of3.2.1 or 3.2.2 shall apply to all the meters tested, according to the accuracy class of the meter. 6.2.3 During the tests, the pressure at the water meter outlet shall be at least 0.03 MPa (0.3 bar). 6.2.4 Errors (of indication) 6.2.4.1 The errors (of indication) of the water meter (in the measurement ofthe actual volume) shall be determined at least at the following flowrates, measured twice at each one: (a) Between Q'I and 1.1 Q'I; (b) Between 0.5 (QI + Q] and 0.55 (QI + Q] )(for Q1.lQ]> 1.6); (c) Between Qpnd 1.1 Q]; (d) Between 0.33 (Q2+ Q) and 0.37 (Q]+ Q); (e) Between 0.67 (Q] + Q) and 0.74 (Q] + Q); (j) Between 0.9 Q, and Q.,; and (g) Between 0.95 Q,and Q,; and for combination meters: (h) Between 0.85 Q" and 0.95 Q" (i) Between 1.05 Q" and l.15 Q" The errors (of indication) observed for each of the above flowrates shall not exceed the maximum permissible errors given in 3.2.1 or 3.2.2. If the error (of indication) observed on one or more meters is greater than the maximum permissible error at one flowrate only, the test at that flowrate shall be repeated. The test shall be declared satisfactory iftwo out of the three results lie within the maximum permissible errors and the arithmetic mean of the results for the three tests at that flowrate is less than or equal to the maximum pennissible error. 6.2.4.2 Ifall the errors (of indication) of the water meter have the same sign. at least one of the errors shall not exceed one half of the maximum permissible error. 6.2.4.3 If the meter is marked as only operating in certain orientations, then the meter shall be tested in these orientations. In the absence of such marks the meter shall be tested in at least three orientations. 6.2.4.4 It is recommended that the characteristic error curve for each water meter be plotted in terms of error against tlowrate, so that the general performance of the water meter over its tlowrate range can be evaluated. 6.2.5 The water meter shall be capable of withstanding the following test pressures without leakage or damage: • 1.6 times the maximum admissible pressure applied for 15 minutes; and • twice the maximum admissible pressure applied for I minute. 6.2.6 the pressure loss values shall be determined at least at the permanent flowrate Q, to check that this pressure loss complies with the provisions of 5.5. 35 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R 49- 1:2006 If the maximum pressure loss occurs at a lower flowrate, then the pressure loss shall be measured at that flowrate. Note: For combination meters, the maximum pressure loss often occurs just before Q". 6.2.7 The water meter shall undergo the endurance tests detailed in Table 4, according to the permanent flowrate Q 3 and the overload flowrate Q, of the meter, simulating service conditions. After each of these tests the errors of the water meter shall again be measured at the flowrates given in 6.2.4.1 and the criteria given in 6.2.7.1 or 6.2.7.2 shall be applied. 6.2.7.1 Accuracy class 1 water meters For accuracy class I water meters, the variation in the error (of indication) curve shall not exceed 2 % for flowrates in the lower flowrate zone (Q, S Q < QJ and I % for flowrates in the upper flowrate zone (QJ S Q sQ). For flowrates in the lower flowrate zone (Q, S Q ( Q). the error (of indication) curve shall not exceed a maximum error limit of ± 4 % for all temperature classes. For flowrates in the upper flowrate zone (Q2 S Q s Q). the error (of indication) curve shall not exceed a maximum error limit of ± 1.5 % for meters of temperature class T30 and ± 2.5 % for all other temperature classes. For the purpose of these requirements the mean values of the errors (of indication) shall apply. 6.2.7.2 Accuracy class 2 water meters For accuracy class 2 water meters, the variation in the error (of indication) curve shall not exceed 3% for flowrates in the lower flowrate zone (Q, S Q < Q), and 1.5% for flowrates in the upper flowrate zone (Q2 S Qs Q). For flowrates in the lower flowrate zone (Q, S Q<Q), the error (of indication) curve shall not exceed a maximum error limit of ± 6 % for all temperature classes. for flowrates in the upper flowrate zone (Q, S Q s Q) the error (of indication) curve shall not exceed a maximum error limit of ± 2.5% for meters of temporature class T30 and ± 3.5 % for all othr temporature classes. For the purpose of these requirements the mean values of the errors (of indication) shall apply. 36 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49- 1:2006 Table 4 Endurance tests Temperature Permanent Test Test water Type of test Number of Time of Time of Class flowrot. flow- temp.r- interrupts pauses test at Q3 rate ature test ± SoC flowr.t. Q3 20°C Dis- 100000 15 s 15 s continuous Q3 S 16 nl31h T30 and T50 orkUh Q4 20 °C Continuous - lOOh Q3 > 16 nl31h Q3 20 °C Continuous - 800 h orkUh Q4 20 ·C Continuous - - 200 h Q3 50°C Dis- 100 000 15 s 15 s continuous All olher Q3 S 16 nl 31h temperature orkUh classes Q4 0.9x MAT Continuous - 100 h Q3 50 °C Continuous Q3 > 16 m3111 800 h ol'kUII Q4 0.9 x MAT Continuous - - 200 h Combination Q3 > 16m31h Q.?2x 20 °C Dis- 50 000 155 15 s meters Qx2 continuous (additional test) ol'kUh Combination Q3 > 16 m31h 0.9Q'1 20 °C Continuous - - 200h meters (where smal I meier has orkUh not been pre approved) .) [Q)l is the number equal to the value of Q3 expressed in m3Jh or kLIh. Notes: I. The orientation(s) oflhe meters 011 test shall be set with reference to Ihe meter orientation(s) claimed by the manufacturer. Duration of start-up and rundown 0.15 [Q3J a) s with a minimum of I s 0.15[Q31 a)s with a minimum of 1 s 3 to 6 s 2. Where a combination meter consists of meters that have becn previously approved, only the Combination meters (additional test) is required. 6.2.8 Static magnetic field test The water meter shall undergo a test for the influence ofa static magnetic field. This test shall apply to all water meters where the mechanical components may be influenced by a magnetic field, and for all meters with electronic components. The test is specified in R 49-2 clause 6.10. The purpose of the test is to ensure compliance with the provisions of3.2 and 4.1.1 in the presence of static magnetic fields. 6.2.9 Documentation 6.2.9. I The application for pattern approval of a water meter or a calculator (including indicating device) or a measurement transducer shall include the following documents: • a description giving the technical characteristics and the principle of operation; • a drawing or photograph of the complete water meter or calculator or measurement transducer; • a list ofthe parts with a description of their constituent materials when these parts have a metrological influence; • an assembly drawing with identification of the different parts; • for meters fitted with correction devices, a description of how the correction parameters are determined; • a drawing showing the location of seals and verification marks; and .a drawing of regulatory markings. • for combination meters that comprise approved meters, the test reports for those meters. 37 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) 6.2.9.2 In addition, the application for pattern approval ofa water meter with electronic devices shall include: .. a functional description of the various electronic devices; .. a flow diagram of the logic, showing the functions of the electronic devices; and .. any document or evidence which shows that the design and construction of the water meter with electronic devices comply with the requirements of this Recommendation, in particular clauses 4.1 and 4.3. 6.2.9.3 The applicant seeking pattern approval shall provide the body responsible for the evaluation with a meter or a calculator (including indicating device) or a measurement transducer which is representative of the final pattern. Additional specimens of the pattern may be considered necessary by the body responsible for the pattern evaluation to estimate the reproducibility of the measurements. 6.2.10 Pattern approval certificate The following information shall appear on the pattern approval certificate: .. name and address of the recipient of the certificate; .. name and address of the manufacturer, if it is not the recipient; • pattern and/or commercial designation; • principal metrological and technical characteristics; • pattern approval mark; .period of validity; • environmental classification, if applicable (see A.2); • information on the location of marks for pattern approval, initial verification and sealing (e.g. a picture or drawing); • list of documents accompanying the pattern approval certificate; and • specific remarks. When applicable, the version of the metrological part of the evaluated software shall be indicated in the pattern approval certificate or in its annexes (technical file). 6.2.11 Modification of an approved pattern 6.2.11.1 The recipient of the pattern approval shall inform the body responsible for the approval of any modification or addition which concerns an approved pattern. 6.2.11.2 Modifications and additions shall be subject to a supplementary pattern approval when they influence, or are likely to influence, the measurement results or the meter's regulatory conditions of use. The body having approved the initial pattern shall decide to which extent the examinations and tests described below shall be carried out on the modified pattern in relation to the nature of the modification. 6.2.11.3 If the body that approved the initial pattern judges that the modifications or additions are not likely to influence the measurement results, this body shall allow the modified meters to be presented for initial verification without granting a supplementary pattern approval. A new or supplementary pattern approval must be issued whenever the modified pattern no longer fulfils the provisions of the initial pattern approval. 6.2.12 Pattern approval of a water meter with electronic devices In addition to the examinations or tests described in the preceding paragraphs, a water meter with electronic devices shall be subject to the following examinations and tests. 6.2.12.1 Design inspection This examination of documents aims at verifying that the design of electronic devices and their checking facilities, if applicable, comply with the provisions of this Recommendation, clause 4 in particular. It includes: 38 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R49-3: (a) An examination of the mode of construction and of the electronic sub-systems and components used, to verilY their appropriateness for their intended use; (b) Consideration of faults likely to occur, to verify that in all considered cases these devices comply with the provisions of 4.1 and 4.3; and (c) Verification of the presence and effectiveness of the test device(s) for the checking facilities, if required. 6.2.12.2 Performance tests The performance tests specified in Annex A aim at verifying that the water meter complies with the provisions of3.2 and 4.1.1 with regard to influence quantities. (a) Performance under the effect of influence factors: When subjected to the effect of influence factors as provided for in Annex A, the equipment shall continue to operate correctly and the errors (of indication) shall not exceed the applicable maximum permissible errors. (b) Performance under the effect of disturbances: When subjected to external disturbances as provided for in Annex A, the equipment shall continue to operate correctly, or significant faults are detected and acted upon by means ofa checking facility. 6.2.12.3 Equipment under test (EUT) Where the electronic devices form an integral part of the water meter, tests shall be carried out on the complete water meter. If the electronic devices of a water meter are in a separate housing, their electronic functions may be tested independently of the measurement transducer of the water meter by simulated signals representative of the normal operation of the meter, in which case the electronic devices shall be tested .in their final housing. In all cases, ancillary equipment may be tested separately. 6.3 Initial verification 6.3.1 Water meters shall undergo the initial verification tests indicated below. verification shall be carried out after pattern approval has been granted. 6.3.2 Water meters of the same size and the same pattern may be tested in series; however in this case the requirements of 6.2.3 (concerning water meter outlet pressure) shall be met for each water meter, and there shall be no significant interaction between water meters. 6.3.3 The errors (of indication) of the water meters in the measurement of actual volume shall be determined for at least the following flowrates: (a) Between QI and 1.1 QI; (b) Between Q2 and 1.1 Q2; and (c) Between 0.9 Q3 and Q3. (d) For combination meters, between 1.05 Qx2 and 1.15 Qx2 However, depending on the shape of the error curve, additional flowrates may be specified in the pattern approval certificate. During a test, the water temperature shall be as specified in Table I (Reference conditions) within a range of ± I O"C. All other influence factors shall be held within the rated operating conditions. 39 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451 (Contd) OlML R 49-3: 6.3.4 The errors (of indication) determined at each of the above flowrates shall not exceed the ma'Cimum permissible errors given in 3.2.1 or 3.2.2. 6.3.5 If all the errors (of indication) of the water meter have the same sign, at least one of the errors shall not exceed one half of the maximum permissible error. 7. TEST METHOD AND TEST REPORT FORMAT 7.1 Test method The methods of examination and testing described in Part 2 (R 49-2 [9]) shall apply to pattern approval and verification of a water meter. In addition, the performance tests in Annex A shall apply to water meters with electronic devices. 7.1.1 Uncertainties in the test methods When a test is conducted, the expanded uncertainty in the determination of the actual volume passing through the water meter shall not exceed one-fifth of the applicable maximum permissible error for pattern approvals, and one-third of the applicable maximum permissible error for initial verifications. The expanded uncertainty shall be estimated according to the Guide to the expression of uncertainty in measurement [10] with a coverage factor, k = 2, . When a test is conducted, the error arising from the resolution of the meter under test shall not exceed the values given in 5.7.4.2.3. 7.2 Test report format The results of pattern approval and verification examinations and tests shall be presented in the format given in the Test Report Format according to Part 3 (R 49-3 [1IJ). ANNEXA PerfOl'mance tests for water meters with electronic devices (Mandatory) A.I General This Annex defines the program of performance tests intended to verify that water meters with electronic devices may perform and function as intended in a specified environment and under specified conditions. Each test indicates, where appropriate, the reference conditions for determining the intrinsic error. These tests supplement any other prescribed test. When the effect of one influence quantity is being evaluated, all other influence quantities are to be held relatively constant, at values close to reference conditions (see 6.1 and A.4). A.2 Environmental c1assitication (see 13al) For each perfonnance test, typical test conditions are indicated which correspond to the climatic and mechanical environmental conditions to which water meters are usually exposed. Water meters with electronic devices are divided into three classes according to climatic and mechanical environmental conditions: • class B for fixed meters installed in a building; • class C for fixed meters installed outdoors; and • class I for mobile meters. 40 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451 (Contd) OIML R49-3: However, the applicant for pattern approval may indicate specific environmental conditions in the documentation supplied to the metrology service, based on the intended use of the instrument. In this case, the metrology service shall carry out performance tests at severity levels corresponding to these environmental conditions. If pattern approval is granted, the data plate shall indicate the corresponding limits of use. Manufacturers shall inform potential users of the conditions of use for which the meter is approved. The metrology service shall verifY that the conditions of use are met. A.3 Electromagnetic environments Water meters with electronic devices are divided into two electromagnetic environments: E I Residential, commercial and light industrial; and E2 Industrial. AA Reference conditions Ambient air temperature: Ambient relative humidity: Ambient atmospheric pressure: Power voltage: Power frequency: 20 DC :!:: 5 DC 60%:!::15% 86 kPa to 106 kPa Nominal voltage (U nom ) Nominal frequency (f"om) During each test, the temperature and relative humidity shall not vary by more than 5 DC or 10 % respectively with in the reference range. These reference conditions should only be applied ifno reference conditions are specified by a relevant regional or national standard designed to meet specific conditions. if specified by such a standard, then the criteria conditions. if specified by such a standard, then the criteria contained therein should be applied. A.S Pattern approval of a calculator When an electronic calculator (including indicating device) is submitted for separate pattern approval, pattern evaluation tests shall be conducted on the calculator (including indicating device) alone, simulating different inputs generated by appropriate standards (e.g. calibrators). A.5.1 Accuracy tests on the indications of measurement results are required. For this purpose, the error obtained on the indication of the result is calculated considering that the true value is the one which takes into account the value of the simulated quantities applied to inputs of the calculator and using standard methods for calculation. The maximum pernlissible errors are those given in 3.2. A.5.2 The examinations and tests for electronic instruments described in 6.2.12 shall be performed. A.6 Performance tests The tests indicated in Table A.I involve the electronic part of the water meter or its devices and may be carried out in any order. The following rules shall be taken into consideration for these performance tests: I) Test volumes Some intluence quantities should have a constant effect on measurement results and not a proportional effect related to the measured volume. The value of the significant fault is related to the measured volume; therefore, in order to be able to compare results obtained in different laboratories, it is necessary to perform a test on a volume corresponding to that delivered in one minute at the overload tlowrate Q4' Some tests, however, may require more than one minute, in which case they shall be carried out in the shortest possible time taking into consideration the measurement uncertainty. 41 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451(Contd) OIML R49-3: 2) Influence of the water temperature Temperature tests concern the ambient temperature and not the temperature of the water used. It is therefore advisable to use a simulation test method so that the temperature of the water does not influence the test results. Table A.I Tests involving the electronic part of the water meter or its devices Table A.l Tests involving the electronic part of the water meter or its devices Test Nature of the Severity level for the class influence quantity (by B C I ref. to OIML D II [3 a]) A.6.1 Dry heat Intlllence factor 3 3 3 A.6.2Cold Influence factor 1 3 3 A.6.3 Damp heat, cyclic Influence factor 1 2 2 A.6,4 Power voltage variation Influence factor 1 1 1 A.6.S Vibration (random) Disturbance . . 2 A.6.6 Mechanical shock Disturbance . . 2 A.6.7 Short time power reductions Disturbance la & Ib la& Ib la& Ib A.6.S Bursts Disturbance 2 or 3 2 or 3 2 or 3 A.6.9 Electrostatic discharge Disturbance 1 1 I A.6.10 Electromagnetic susceptibility Disturbance 2 or 3 2 or 3 2 or 3 A.6.l Dry heat Test method: Object of the test: References: Test procedure in briefF l Test severities: Dry heat (non condensing) To verilY compliance with the provisions in 3.2 under conditions of high ambient air temperature. IEC 60068-2-2 (1974-0 I), -ami (1993-02), -am2 (1994-05). Environmental testing. Part 2. Tests. Tests B. Dry heat. Section 4 -Test Bd: Dry heat for heat dissipating specimen with gradual change of temperature [12]. IEC 60068-3-1 (1974-0 I), -IA (1978-01). Basic environmental testing procedures. Part 3: Background information. Section I: Cold and dry heat tests [13]. IEC 60068-1 (1988-06), -am I (1992-04). Environmental testing. Part I: General and guidance [14]. The test consists of exposure of the EUT to a temperature of 55 °C under "free air" conditions for a 2-hour period, after the EUT has reached temperature stability. The EUT shall be tested at the reference flowrate (or simulated flowrate) and: • at the reference temperature of 20°C following conditioning; • at the temperature of 55 DC, 2 hours after temperature stabilization; and • after recovery of the EUT at the reference temperature of 20 DC. I) Temperature: severity level 3: 55°C 2) Duration: 2 hours Number of test cycles: One cycle Maximum allowable variations: All functions shall operate as designed and all the errors (of indication) measured during the application of the influence factor shall be within the maximum permissible error of the upper flowrate zone. 42 Weights and Measures (Metrological Control of Water Meters) OIML R49-3: A.6.2 Cold Test method: Object of the test References: GN. No. 451(Contd) Cold To verify compliance with the provisions in 3.2 under conditions of low ambient air temperature. IEC 60068-2-1 (1990-05), -ami (1993-02), -am2 (J 994-06). Environmental testing. Part 2.1 Tests. Tests A. Cold. Section 3 -Test Ad: Cold for heat-dissipating specimen with gradual change of temperature [I 5]. IEC 60068-3-1 (J 974-0 I), -I A (1978-01). Basic environmental testing procedures. Part 3: Background information. Section I: Cold and dry heat tests [13]. (7) This test procedure has been given in condenced torm, for information only, and is adapted from the referenced iec-publication. before conducting the test, the applicable publicable publication should be consulted. this comment also applies to the test procedures hereafter. Test procedure in brief: Test severities: Number of test cycles: IEC 60068-1 (1988-06), -am 1 (J 992-04). Environmental testing. Part I: General and guidance [14]. The test consists of exposure of the EUT to a temperature of either 25 DC (classes C or I) or + 5 DC (class B) under "free air" conditions for a 2 hour period after the EUT has reached temperature stability. The EUT shall be tested at the reference flowrate (or simulated flowrate): • at the reference temperature of20 DC following conditioning; • at a temperature of -25 DC or + 5 DC, 2 hours after temperature stabilization; and • after recovery of the EUT at the reference temperature of 20 DC. I) Temperature: 2) Duration: 2 hours One cycle severity leve 1 I : + 5 DC severity level 3: -25 DC Maximum allowable variations: All functions shall operate as designed and all the errors (of indication) measured during application of the influence factor shall be within the maximum permissible error of the upper flowrate zone. A.6.3 Test method: Object of the test: References: Test procedure in brief: Damp heat, cyclic Damp heat, cyclic (condensing) To verify compliance with the provisions in 3.2 under conditions of high humidity when combined with cyclic temperature changes. IEC 60068-2-30 (1980-0 I), -ami (1985-08). Basic environmental testing procedures. Part 2: Tests. Test Db and guidance: Damp heat, cyclic (12h + 12h cycle), test variant I [16]. IEC 60068.3-4 (2001-08). Environmental Testing. Part 3-4: Supporting documentation and guidance -Damp heat tests [17] The test consists of exposure of the EUT to cyclic temperature variations between 25 DC and the upper temperature of 55 DC (classes C or I) or 40°C (class B), maintaining the relative humidity above 95 % during the temperature changes and during the phases at low temporature, and at 93% at the upper temperature phases. 43 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R49-3: Test severities: Number of test cycles: Condensation shall occur on the eut during the temporature rise. A standard stablilizing period before and recovery after the cyclic exposure is indicated in iec 60068-2-30 [16] the power supply is turned off when the influence factor is applied. for water meters that contain internal batteries, normally the battery should not be removed. however, advice regarding this should be sought from the manufacturer. A note of this must be recorded on the test certificate. I) Upper temperature: severity levell: 40"C severity level 2: 55°C 2) Duration: 24 hours Two cycles Maximum allowable variations: After the application of the influence factor and recovery all functions shall operate as designed and all the errors (of indication) measured shall be within the maximum permissible error of the upper flowrate zone. A.6.4 A.6.4.1 Test method: Object of the test: References: Test procedure in brief: Test serverities: Power voltage variation Water meters powered by direct AC or AC/DC converters Variation in AC mains power supply (single phase) To verifY compliance with the provisions in 3.2 under conditions of varying AC mains power supply. IEC 61000-4- I I (1994-06), -am I (2000-11). Electromagnetic Compatibility (EMC). Part 4: Testing and measurement techniques. Section I I: Voltage dips, short interruptions and voltage variations immunity tests [IS] IEC/TR3 61000-2-1 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 1: Description of the environment -Electromagnetic environment for low-frequency conducted disturbances and signaling in public power supply systems [19] IEC 61000-2-2 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 2: Compatibility levels for low-frequency conducted disturbances and signaling in public low-voltage power supply systems [20] IEC 61000-4-1 (2000-04). Electromagnetic Compatibility (EMC). Part 4-1: Testing and measurement techniques - Overview of IEC 61000-4 series [21] IEC 60654-2 (1979-0 I) -am I (1992-10). Operating conditions for industrial process measurement and control equipment. Part 2: Power [22] The test consists of exposure of the EUT to power voltage variations, while the EUT is operating under normal atmospheric conditions. Single voltage: Mains voltage: Voltage range: Mains voltage: upper limit: V + 10% lower limit: V:::,: -15% upper limit: V u + 10% lower limit: VI - 15% 44 Weights and Measures (Metrological Control of Water Meters) GN. No. 451(Contd) OIML R49-3: Maximum allowable variations: All functions shall operate as designed and all errors (of indication) measured during the application of the influence factor shall be within the maximum permissible errors of the upper flowrate zone. A.6.4.2 Test method: Objective of the test: References: Test procedure in brief: Test severities: Water meters powered by DC batteries Variation in DC battery power supply To verify compliance with the provisions in 3.2 under conditions of varying DC power supply. None available The meter error (of indication) shall be measured with the maximum and the minimum operating voltages of the battery, as specified by the water meter supplier, applied throughout the test. Voltage: upper limit (battery maximum): Urn", lower limit (battery minimum): U"'i" Maximum allowable variations: All functions shall operate as designed and all errors (of indication) measured during the application of the influence factor shall be within the maximum permissible errors of the upper flowrate zone. A.6.S Test method: Object of the test: References: Test procedure in brief: Test severities: Duration per axis: Vibration (random) Random vibration To verify compliance with the provisions in 3.2 under conditions of random vibration. This test should normally apply to mobile installations only. IEC 60068-2-64 (1993-05), corr. I (1993-10). Environmental testing. Part 2: Test methods. Test Fh: Vibration, broad-band random (digital control) and guidance (23) IEC 60068-2-47 (1999-10) Environmental testing. Part 2-47: Test methods. Mounting of components, equipment and other articles for vibration, impact and similar dynamic tests. [24] The test consists of exposure of the EUT to the required vibration level for the defined period of time. The EUT shall, in turn, be tested in three, mutually perpendicular axes mounted on a rigid fixture by its normal mounting means. The EUT shall normally be mounted so that the gravitational force acts in the same direction as it would in normal use. Where the effect of gravitational force is not important the EUT may be mounted in any position The EUT shall not be operating and not filled with liquid when the disturbance is applied. Severity level 2. I) Frequency range: 10Hz -ISO Hz 2) Total RMS level: 7m .S-2 3) ASD level 10 -20 Hz: 1m'. S-3 4) ASD level 20 -ISO Hz: -3 dB/octave 5) Number of axes: 2 minutes. 45 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49-3: Maximum allowable variations: After the application of the disturbance and recovery, all functions shall operate as designed and all the errors (of indication) measured shall be within the maximum permissible errors of the upper flowrate zone. A.6.6 Test method: Object of the test: References: Test procedure in brief: Test severities: Mechanical shock Dropping onto face To verify compliance with the provisions in 3.2 under conditions of mechanical shocks. This test should normally apply to mobile installations only. IEC 60068-2-31 (1969-01), -am 1 (1982-01). Environmental testing. Part 2: Tests. Test Ec: Drop and topple, primarily for equipment-type specimens [25] IEC 60068-2-47 (1999-10). Environmental testing. Part 2-47: Test methods. Mounting of components, equipment and other articles for vibration, impact and similar dynamic tests [24] The EUT, placed in its normal position of use on a rigid surface, is tilted towards one bottom edge and is then allowed to fall freely on to the test surface. The EUT shall not be operating and not filled with liquid when the disturbance is applied. Severity level 2. Height of fall.: 50 mm "Height of fall: distance between the opposite edge and the test surface However, the angle made by the bottom and the test surface shall not exceed 30° Number of falls (on each bottom edge): One. Maximum allowable variations: After the application ofthe disturbance and recovery, all functions shall operate as designed and all the errors (of indication) measured shall be within the maximum permissible errors of the upper flowrate zone. A.6.7 Test method: Object of the test: References: Short time power reductions Short time interruptions and reductions in mains Voltage. To verify compliance with the provisions in 3.2 under conditions of short time mains voltage interruptions and reductions. IEC 61000-4-11 (1994-06), -am 1 (2000-11). Electromagnetic Compatibility (EMC). Part 4: Testing and measurement techniques. Section 11: Voltage dips, short interruptions and voltage variations immunity tests [18] IECITR3 61000-2-1 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 1 : Descriution of the environment -Electromagnetic environment for low-frequency conducted disturbances and signaling in public power supply systems [19] IEC 61000-2-2 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 2: Compatibility levels for low-frequency conducted disturbances and signaling in public low-voltage power supply systems [20] IEC 61000-4-1 (2000-04). Electromagnetic Compatibility (EMC). Part 4-1: Testing and measurement techniques - Overview oflEC 61000-4 series [21] 46 Weights and Measures (Metrological Control a/Water Meters) OIMLR49-3: fest procedure in brief: Test severities: Number of test cycles: GN. No. 451(Contd) The test consists of subjecting the EUT to voltage interruptions from nominal voltage to zero' voltage for a duration equal to half a cycle of line frequency (severity level I a), and reductions from nominal voltage to 50 % of nominal for a duration equal to one cycle of line frequency (severity level 1 b). The mains voltage interruptions and reductions shall be repeated ten times with a time interval of at least ten seconds. 100 % voltage interruption for a period equal to half a cycle. 50 % voltage reduction for a period equal to one cycle. At least ten interruptions and ten reductions, each with a minimum often seconds between tests. The interruptions and reductions are repeated throughout the time necessary to perform the whole test. For this reason, more than ten interruptions and reductions may be necessary. Maximum allowable variations: The difference between the error (of indication) during the test and the intrinsic error shall not exceed the value given in 2.2.10 or significant faults are detected and acted upon by means of a checking facil ity. A.6.S Test method: Object of the test: References: Test procedure in brief: Test severities: Test duration: Bursts Electrical bursts To verify compliance with the provisions in 3.2 under conditions where electrical bursts are superimposed on the mains voltage. IEC/TR3 61000-2-1 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 1: Description of the environment -Electromagnetic environment for low-frequency conducted disturbances and signaling in public power supply systems [19) IEC 61000-2-2 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 2: Compatibility levels for low-frequency conducted disturbances and signaling in public low-voltage power supply systems (20) IEC 61000-4-1 (2000-04). Electromagnetic Compatibility (EMC). Part 4-1: Testing and measurement techniques - Overview of IEC 6 I 000-4 series (21) IEC 61000-4-4 (1995-0 I), -am I (2000-11) level 2. Electromagnetic Compatibility (EMC). Part 4: Testing and measurement techniques. Section 4: Electrical fast transient/burst immunity tests. Basic EMC publication. (26) The test consists of subjecting the EUT to bursts of double exponential waveform transient Voltages. Each spike shall have a rise time of 5 ns and a half amplitude dur,ation of 50 ns. The burst length shall be 15 ms and the burst period (repetition time interval) shall be 300 ms. All bursts shall be applied asynchronously in asymmetrical mode (common mode). EI Amplitude (peak value) I 000 V E2 Amplitude (peak value) 2000 V The bursts should be applied for at least one minute during the same measurement or simulated measurement for each polarity. Maximum allowable variations: The difference between the error (of indication) during the test and the intrinsic error shall not exceed the value given in 2.2.10 or significant faults are detected and acted upon by means of a checking facility. 47 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R 49-3: A.6.9 Test method: Object of the test: References: Test procedure in brief: Test severities: Number oftest cycles: Electrostatic discharge Electrostatic discharge To verify compliance with the provisions in 3.2 under conditions of direct and indirect electrostatic discharges. IECITR3 61000-2-1 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section I: Description of the environment -Electromagnetic environment for low-frequency conducted disturbances and signaling in public power supply systems [19] IEC 61000-2-2 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 2: Compatibility levels for low-frequency conducted disturbances and signaling in public low-voltage power supply systems [20] IEC 61000-4-1 (2000-04). Electromagnetic Compatibility (EMC). Part 4-1: Testing and measurement techniques - Overview of lEC 61000-4 series [21] lEC 61000-4-2 (1999-05), -am2 (2000-1 I) level 3. Electromagnetic Compatibility (EMC). Part 4-2: Testing and measurement techniques. Electrostatic discharge immunity tests [27]. A capacitor of 150 pF is charged by a suitable DC voltage source. The capacitor is then discharged through the EUT by connecting one terminal to ground (chassis) and the other via 330 ohms to surfaces which are normally accessible to the operator. The test includes the paint penetration method, if appropriate. For direct discharges the air discharge method shall be used where the contact discharge method cannot be applied. 8 k V for air discharges 6 kV for contact discharges At each test point, at least ten direct discharges shall be applied at intervals of at least ten seconds between discharges, during the same measurement or simulated measurement. For indirect discharges, a total often discharges shall be applied on the horizontal coupling plane and a total often discharges for each of the various positions of the vertical coupling plane. Maximum allowable variations: The difference between the error (of indication) and the intrinsic error shall not exceed the value given in 2.2.10 or significant faults are detected and acted upon by means of a checking facility. A.6.I0 Test method: Object of the test: References: Where a meter has been proven to be immune for electrostatic discharges, within the rated operating conditions for f1owrate, the metrological authority shall be free to choose a f10wrate of zero during the electrostatic discharge test. During a zero f10wrate test the meter totalization shall not change by more than the value of the verification scale interval. Electromagnetic susceptibility Electromagnetic fields (radiated) To verify compliance with the provisions in 3.2 under conditions of electromagnetic fields. IEcrrR3 61000-2-1 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section I: Description of the environment. Electromagnetic 48 OlMLR49 Weights and Measures (Metrological Control of Water Meters) Test procedure in brief: Test severities: Field strength: Modulation: GN. No. 45J(Contd) environment for low-frequency conducted disturbances and signaling in public power supply systems [19] IEC 61000-2-2 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 2: Compatibility levels for low-frequency conducted disturbances and signaling in public low-voltage power supply systems [20] IEC 61000-4-1 (2000-04). Electromagnetic Compatibility (EMC). Part 4-1 : Testing and measurement techniques. Overview of lEC 61000-4 series [21] IEC 61000-4-3 (1998-11), -am2 (2000-11). Electromagnetic Compatibility (EMC). Part 4-3: Testing and measurement techniques. Radiated, radio frequency, electromagnetic field immunity tests [28] The EUT shall be exposed to the electromagnetic field strength as specified by the severity level. The field strength can be generated in various ways: • the strip line is used at low Jrequencies below 30 MHz (or in some cases 150 MHz) for small EUTs; • the long wire is used at low frequencies (below 30 MHz) for larger EUTs; • dipole antennas or antennas with circular polarization placed I m from the EUT are used at high frequencies. The specified field strength shall be established prior to the actual testing without the EUT in the field. The field shall be generated in two orthogonal polarizations. If antennas with circular polarization i.e. log-spiral or helical antennas are used to generate the electromagnetic field, a change in the position of the antennas is not required. When the test is carried out in a shielded enclosure, to comply with international laws prohibiting interference to radio communications, care should be taken to handle reflections trom the walls. anechoic shielding may be necessary. Frequency range: 26 MHz -I 000 MHz EI3 Vim E2 10 Vim 80 % AM, I kHz sine wave Maximum allowable variations: The difference between the error (of indication) during the test and the intrinsic error shall not exceed the value given in 2.2.10 or significant faults are detected and acted upon by means ofa checking facility. 49 Weights and Measures (Metrological Control of Water Meters) GN. No. 451 (Contd) OIML R49-3: Annex B Terms used to characterize a water meter (Informative) B.l Definitions of terms used in Figure B.l QI' Q" Q" and Q, are defining characteristics for the metrological control of water meters as described in clause 2 of this Recommendation. Qu Q" Q~ and Q" are related to the actual error curve of a water meter and are defined below. B.I.I Continuous flow rate, Q, Highest flowrate at which a water meter can actually operate in a satisfactory manner, within maximum permissible error, under normal conditions of use, i.e. 'under steady or intermittent flow conditions. B.1.2 High flow rate Q h Highest flowrate at which a water meter can actually operate in a satisfactory manner, within the maximum permissible error, for a short period of time without deteriorating. B.1.3 Low flow rate, Q L Lowest flowrate at which a water meter can give indications that satisfy requirement! concerning the maximum permissible errors in the lower flowrate zone (mpel). B.I.4 Inter'mediate flow rate, Q, Highest flowrate in the lower flowrate zone at which the water meter error (of indication) goes from above to below the maximum permissible error of the upper flowrate zone (mpeu). B.1.5 Permauent flow rate, QJ Highest flowrate within the rated operating conditions, at which the water meter is required to operate in a satisfactory manner within the maximum permissible error. B.I.6 Overload flow rate, Q, Highest flowrate at which the water meter is required to operate for a short period of time, within its maximum permissible error, whilst maintaining its metrological performance when it is subsequently operated within its rated operating conditions. B.I.7 Minimum flow rate, Q, Lowest flowrate at which the water meter is required to operate within the maximum permissible error. B.I.8 Transitional flow rate, Q, Flowrate which occurs between the permanent flowrate Q" and the minimum flowrate Q" that divides the flowrate range into two zones, the upper flowrate zone and 'the lower flowrate zone, each cliaracterized by its own maximum permissible error. B.2 Influeuce Quantities influence quantities may alter the error characteristics and the correct functioning of a water meter. Figure B.I shows a representation of some of the influence quantities relevant to water meters, where the points and their adjacent bars are examples of the reference values of influence quantities and their tolerances. The reference values and their tolerances lie within the rated operating conditions of the meter and are applied during performance tests. 50 Weights and Measures (Metrological Control of Water Meters) GN. No. 45 J (Contd) OIMLR 49-3: Sample water meter en-or curve (with requirements) QI' Q2' Q,l' and Q4 pertain to requirements for water meters as defined in Section 2. Ql,' Q" Q" and Q" pertain to the actual performance of the meter design as defined in Annex B. Volume Flow Indication Error % Limiting Conditions (L'C')I If ... +mpe, +mpe. mpe, mpe, Innuence Quantities Working Pressure Working Temperature Tw Ambient Temperature ------~----~--~--------~--~. Ta Ambient Humidity ~--------~---.~ Rated Operating Conditions (R.O.C.) Limiting Conditions (L.C.) l 'I Flow Rate (Q) Figure B.l 51 Weights and Measures (Metrological Control a/Water Meters) GN. No. 451(Contd) OIML R49-3: Bibliography [I) International Vocabulary of Basic and General Terms in Metrology (VIM) (1993). BIPM, IEC, IFCC, ISO, IUPAC, IUPAP and OIML. International Organization for Standardization, Geneva. [2) International vocabulary of terms in legal metrology (VIML) (2000). OIML, Paris. [3] OIML International Document D I I. General Requirements for electronic measuring instruments. OIML, Paris*. [3a] OIML International Document D I I (1994) General Requirements for electronic measuring instruments. OIML, Paris. [4] ISO 3:1973. Preferred numbers -Series of preferred numbers. International Organization for Standardization, Geneva. [5) ISO 4006: 1991. Measurement of fluid flow in closed conduits -Vocabulary and symbols. International Organization for Standardization, Geneva. [6] OIML International Recommendation R 117 (1995). Measuring systems for liquids other than water. OIML, Paris. [7] ISO 6817: 1992. Measurement of conductive liquid !low in closed conduits -Method using electromagnetic flow-meters. International Organization for Standardization, Geneva. [8] OIML International Document D 4. Installation and storage conditions for cold water meters. OIML, Paris. [9] NMI Recommendation R 49-2 (2007). Water meters intended for the metering of cold potable water and hot water. Part 2: Test methods. National Measurement Institute, Sydney. [10) Guide to the expression of uncertainty in measurement (GUM) (1995). BIPM, IEC, IFCC, ISO, IUPAC, IUPAP and OIML. International Organization for Standardization, Geneva. [II] NMI Recommendation R 49-3 (2007). Water meters intended for the metering of cold potable water and hot water. Part 3: Test Report Format. National Measurement Institute, Sydney. [12] IEC 60068-2-2 (1974-0 I). Amendments IEC 60068-2-2-aml (1993-02) and IEC 60068-2-2-am2 (1994 05). Environmental testing. Part 2. Tests. Test B. Dry heat. Section 4 -Test Bd: Dry heat for heat-dissipating specimen with gradual change of temperature. International Electrotechnical Commission, Geneva [13) IEC 6006S-3-1 (1974-0 I). First Supplement: IEC 6006S-3-IA (l97S-0 I). Basic environmental testing procedures. Part 3: Background information. Section I -Cold and dry heat tests. International Electrotechnical Commission, Geneva. [14) lEC 6006S-1 (198S-06). Amendment IEC 6006S-I-aml (1992.04). Environmental testing. Part I: General and guidance. International Electrotechnical Commission, Geneva [15] IEC 6006S-2-1 (1990-05). Amendments IEC 6006S-2-I-aml (1993-02) and IEC 6006S-2-I-am2 (1994 06). Environmental testing. Part 2.1 Tests. Test A. Cold. Section 3 -Test Ad: Cold for heat-dissipating specimen with gradual change of temperature. International Electrotechnical Commission, Geneva. [16) IEC 60068-2-30 (19S0-0 I). Amendment IEC 60068-2-30-aml (1985-08). Basic environmental testing procedures. Part 2: Tests. Test Db and guidance: Damp heat, cyclic (12 + 12-hour cycle). International Electrotechnical Commission, Geneva [17] IEC 60068-3-4 (2001-08). Environmental Testing. Part 3-4: Supporting documentation and guidance Damp heat tests. International Electrotechnical Commission, Geneva. [IS] lEC 61000-4-11 (2004-03). Electromagnetic compatibility (EMC). Part 4: Testing and measurement techniques. Section II: Voltage dips, short interruptions and voltage variations immunity tests. International Electrotechnical Commission, Geneva 52 Weights and Measures (Metrological Control of Water Meters) GN. No. 45 J (Con/d) OIMLR49-3: [19) IEC/TR3 61000-2-1 (1990-05). Electromagnetic Compatibility (EMC). Part 2: Environment. Section I: Description of the environment. Electromagnetic environmcnt for low-frequcncy conducted disturbanccs and signaling in public power supply systems. International Electrotechnical Commission, Geneva [20) IEC 61000-2-2 (2002-03). Electromagnetic Compatibility (EMC). Part 2: Environment. Section 2: Compatibility levels for low-frequency conducted disturbanccs and signaling in public low-voltage power supply systcms. International Electrotechnical Commission, Geneva [21) IEC 6 I 000-4- I (2000-04). Electromagnetic compatibility (EMC). Part 4-1: Testing and measurcment techniques. Overview oflEC 61000-4 scrics. International Electrotechnical Commission, Gcneva [22) IEC 60654-2 (1979-0 I). Amendment IEC 60654-2-aml (1992-10). Operating conditions for industrial process measurement and control cquipment. Part 2: Power. International Electrotechnical Commission, Geneva [23) IEC 60068-2-64 (1993-05). Environmental testing. Part 2: Test methods. Test Fh: Vibration, broad-band random (digital control) and guidancc. International Elcctrotechnical Commission, Geneva [24) IEC 60068-2-47 (1999-10). Environmental testing. Part 2-47: Test methods. Mounting of components, equipment and other articles for vibration, impact and similar dynamic tcsts. International Electrotechnical Commission, Geneva. [25) IEC 60068-2-3 I (1969-0 I). Amendment IEC 60068-2-3 I-ami (1982-0 I). Environmental testing. Part 2: Tests. Test Ec: Drop and topple, primarily for equipmcnt-type specimens. International Elcctrotechnical Commission, Geneva. [26) I EC 61000-4-4 (2004-07). Electromagnetic compatibility (EMC). Part 4: Testing and measurement techniques. Section 4: Electrical fast transient/burst immunity test. Basic EMC publication. International Electrotechnical Commission. Gcneva. [27) IEC 61000-4-2 (1995-01).with Amendment IEC 61 000-4-2-aml (1998-01) and Amendment IEC 61000 4-2- arn2 (2000-11) level 3. Electromagnetic Compatibility (EMC). Part 4-2: Testing and measurement techniques. Electrostatic discharge immunity tests. Consolidated edition IEC61000-4-2(200 1-04 ed 1.2 Intcrnational Electrotechnical Commission, Geneva. [28) IEC 61000-4-3 consolidated Edition 2.1 (2002-09) with amendment I (2002-08). Electromagnetic Compatibility (EMC). Part 4-3: Testing and measurement techniques. Radiated, radio-frequency, electromagnetic field immunity tests. International Electrotechnical Commission, Geneva. * When a document is referenced with a date, the reference applies to that version. If no issue date or version is given, the current version of the standard should be used. Dar es Salaam, 09th July,2014 53 ABDALLAH O. KIGODA Minister for Industry and Trade 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1