DRAFT DR 1 RECOMMENDATION - DANAK

1 SSUUBBMMIITTTTEEDDFFOORR CCIIMMLLAAPPPPRROOVVAALL41st CIMLR evision of R 49-1 Water meters intended for the metering of cold potable water and hot waterPart 1: Metrological and technical requirementsOIML DR 1 - Revision R 49-1 - 41st CIML - Cape Town 200641st CIML Meeting Cape Town 2006 (Item )DR 1 ORGANISATIONINTERNATIONALEDEM TROLOGIEL GALEINTERNATIONALORGANIZATIONOFLEGALMETR OLOGYDRAFTRECOMMENDATION 2 Contents Foreword .. 4 1 Scope .. 5 2 Terminology .. 5 Water meter and its constituents .. 5 Metrological characteristics .. 6 Operating conditions .. 7 Test conditions .. 8 Electronic and electrical equipment ..9 3 Metrological requirements .. 10 Values of Q1, Q2, Q3 and Q4 ..10 Accuracy class and maximum permissible 10 Requirements for meters and ancillary 10 4 Water meters equipped with electronic devices.

2 13 General requirements .. 13 Power supply .. 13 Checking facilities .. 14 5 Technical requirements .. 15 Materials and construction of water meters .. 17 Adjustment and correction .. 17 Installation conditions .. 17 Rated operating conditions .. 17 Pressure loss .. 18 Marks and inscriptions .. 18 Indicating device .. 18 Verification marks and protection devices .. 20 6 Metrological controls .. 21 Reference conditions .. 21 Pattern approval .. 21 Initial verification .. 26 7 Test method and test report format .. 27 Test method .. 27 Test report format .. 27 Annex A Performance tests for water meters with electronic devices (Mandatory) .. 28 Annex B Terms used to characterize a water meter (Informative) .. 40 Bibliography .. 42 3 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.

3 The two 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; the oiml Member States shall implement these recommendations to the greatest possible extent; international Documents ( oiml D), which are informative in nature and intended to improve the work of the metrological services. oiml DRAFT recommendations and Documents are developed by technical committees or subcommittees which are formed by the Member States. Certain international and regional institutions also participate on a consultation basis. Cooperative agreements are established between oiml and certain institutions, such as ISO and IEC, with the objective of avoiding contradictory requirements; consequently, manufacturers and users of measuring instruments, test laboratories, etc.

4 May apply simultaneously oiml publications and those of other institutions. international recommendations and international Documents are published in French (F) and English (E) and are subject to periodic revision. This publication - reference oiml R 49-1, Edition 200? - was developed by the Subcommittee TC 8/SC 5 Water meters. This version supersedes oiml R 49-1 Water meters intended for the metering of cold potable water. Part 1:Metrological and technical requirements (Edition 2003) and oiml R 72 Hot water meters (Edition 1985) It was approved for final publication by the international Committee of Legal Metrology in 200?. The present publication - reference oiml R 49-1, Edition 200? - is an amended version of the 2003 Edition to incorporate requirements for hot water and combination meters.

5 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 M trologie L gale 11, rue Turgot - 75009 Paris - France Telephone: 33 (0)1 48 78 12 82 Fax: 33 (0)1 42 82 17 27 E-mail: Internet: BIML note: This obligatory Foreword to oiml recommendations will be finalized when edited by the BIML for publishing. 4 Water meters intended for the metering of cold potable water and hot water Part 1: Metrological and technical requirements 1 Scope 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.

6 These water meters shall incorporate devices which indicate the integrated volume. 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. This RECOMMENDATION 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.

7 However, national or international regulations may make some ancillary devices mandatory in relation to the utilization of the water meter. In addition to the metrological and technical requirements included in this Part 1 (R 49-1) the methods of examination and testing are included in Part 2 (R 49-2) and the test report format is included in Part 3 (R 49-3). 2 Terminology Many of the definitions used in this RECOMMENDATION conform to the international Vocabulary of Basic and General Terms in Metrology (VIM) [1], the international Vocabulary of Terms in Legal Metrology (VIML) [2] and oiml international Document D 11 [3]. For the purposes of this RECOMMENDATION , the definitions below shall apply.

8 Water meter and its constituents Water meter An instrument intended to measure continuously, memorize and display the volume of water passing through the measurement transducer at metering conditions. Note 1. 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 flowrate passing through the meter, automatically directs the flow through either the small or large meter or both.

9 Meter reading is obtained from two independent totalizers or one totalizer, which adds up the values from both water meters. Measurement transducer A 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. Flow sensor or volume sensor That part of the water meter (such as a disc, piston, wheel, turbine element, 5 electromagnetic coil, or other transducer) which senses the flowrate or volume of water passing through the meter.

10 Calculator A 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. Indicating device A 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. Adjustment device A 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.