Gas meters Conversion devices

Transcription

1 BRITISH STANDARD BS EN :2005 +A2:2010 Gas meters Conversion devices Part 1: Volume conversion ICS

2 National foreword This British Standard is the UK imlementation of EN :2005+A2:2010. It suersedes BS EN :2005 which is withdrawn. The start and finish of text introduced or altered by amendment is indicated in the text by tags!". Tags indicating changes to CEN text carry the number of the CEN amendment. For examle, text altered by CEN amendment A1 is indicated by!". The UK articiation in its rearation was entrusted to Technical Committee GSE/25, Gas meters. A list of organizations reresented on GSE/25 can be obtained on request to its secretary. This ublication does not urort to include all the necessary rovisions of a contract. Users are resonsible for its correct alication. Comliance with a British Standard cannot confer immunity from legal obligations. This British Standard was ublished under the authority of the Standards Policy and Strategy Committee on 28 June 2005 BSI 2011 Amendments/corrigenda issued since ublication Amd. No. Date Comments October 2006 Imlementation of CEN amendment A1: January 2011 Imlementation of CEN amendment A2:2010 ISBN

3 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN :2005+A2 October 2010 ICS Suersedes EN :2005 English Version Gas meters - Conversion devices - Part 1: Volume conversion Comteurs de gaz - Disositifs de conversion - Partie 1: Conversion de volume Gaszähler - Umwerter - Teil 1: Volumenumwertung This Euroean Standard was aroved by CEN on 15 March 2005 and includes Amendment 1 aroved by CEN on 6 July 2006 and Amendment 2 aroved by CEN on 19 Setember CEN members are bound to comly with the CEN/CENELEC Internal Regulations which stiulate the conditions for giving this Euroean Standard the status of a national standard without any alteration. U-to-date lists and bibliograhical references concerning such national standards may be obtained on alication to the CEN Management Centre or to any CEN member. This Euroean Standard exists in three official versions (English, French, German). A version in any other language made by translation under the resonsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyrus, Czech Reublic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Sain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exloitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN :2005+A2:2010: E

4 Contents Page Foreword Scoe Normative references Terms, definitions and symbols Terms and definitions Symbols !Classification" Mechanical classes Electromagnetic environmental classes Princile of measurement Conversion as a function of temerature Conversion as a function of ressure and temerature Conversion as a function of ressure, temerature and deviation from the ideal gas law Correction of the volume at measurement conditions Rated oerating conditions Secified field of measurement Secified measurement range for gas ressure Secified measurement range for gas temerature Gas characteristics !Base conditions" !Environmental conditions" Ambient temerature range Humidity range !Mechanical environment" Electromagnetic environment Power suly Construction requirements General Casings Indications General Electronic indicating device Inuts for volume conversion Battery owered conversion device Security devices and alarms Installation requirements General Temerature transducer Pressure transducer Performance Reference conditions Rated oerating conditions Maximum ermissible errors General Error of conversion Secific errors for a gas-volume conversion device, tye Conditions of matching the constituent elements of a conversion device tye Influence factors

5 8.6 Disturbances Durability !Reeatability" !Reliability" Tests of conformity Verification of the construction requirements Verification of the erformance requirements Test conditions Samles of gas volume conversion device tye 1 required for testing Samles of gas volume conversion devices tye 2 required for testing Test reort Marking !Installation and oerating instructions" Annex A (normative) Tye test A.1 General conditions A.1.1 General A.1.2 Additional conditions secific to gas volume conversion devices tye A.1.3 Additional conditions secific to gas-volume conversion devices tye A.1.4 Test rocedures A.1.5 Verification of the construction requirements A.2 Accuracy tests under reference conditions A.2.1 Objective A.2.2 Reference to documents A.2.3 Procedure A.2.4 Accetance criteria A.3 Effect of ambient temerature A.3.1 Objective A.3.2 Reference to documents A.3.3 Procedure A.3.4 Accetance criteria A.4 Effect of dam heat, steady state test A.4.1 Objective A.4.2 Reference to documents A.4.3 Procedure A.4.4 Accetance criteria A.5 Effect of dam heat, cyclic test A.5.1 Objective A.5.2 Reference to documents A.5.3 Procedure A.5.4 Accetance criteria A.6 Electrical ower variation A.6.1 Objective A.6.2 Reference to documents A.6.3 Procedure A.6.4 Accetance criteria A.7 Short time ower reductions A.7.1 Objective A.7.2 Reference to documents A.7.3 Procedure A.7.4 Accetance criteria A.8 Electrical bursts A.8.1 Objective A.8.2 Reference to documents A.8.3 Procedure A.8.4 Accetance criteria A.9 Electromagnetic suscetibility A.9.1 Objective A.9.2 Reference to documents A.9.3 Procedure

6 A.9.4 Accetance criteria A.10 Electrostatic discharges A.10.1 Objective A.10.2 Reference to documents A.10.3 Procedure A.10.4 Accetance criteria A.11 Overload of ressure (only for tye 1 and ressure transducers) A.11.1 Objective A.11.2 Reference to documents A.11.3 Procedure A.11.4 Accetance criteria A.12 Effect of vibrations A.12.1 Objective A.12.2 Reference to documents A.12.3 Procedure A.12.4 Accetance criteria A.13 Effect of shocks A.13.1 Objective A.13.2 Reference to documents A.13.3 Procedure A.13.4 Accetance criteria A.14 Overload of ressure (mechanical) A.14.1 Objective A.14.2 Reference to documents A.14.3 Procedure A.14.4 Accetance criteria A.15 Durability A.15.1 Objective A.15.2 Reference to documents A.15.3 Procedure A.15.4 Accetance criteria A.16 Alarms oeration A.16.1 Objective A.16.2 Reference to documents A.16.3 Procedure A.16.4 Accetance criteria A.17!Reeatability A.17.1 Objective A.17.2 Reference to standards A.17.3 Procedure A.17.4 Accetance criteria" A.18 #Short time DC ower variations A.18.1 Objective A.18.2 Reference to standards A.18.3 Procedure A.18.4 Accetance criteria$ A.19 #Surges on suly lines and/or signal lines A.19.1 Objective A.19.2 Reference to standards A.19.3 Procedure A.19.4 Accetance criteria$ A.20 #Power frequency magnetic field A.20.1 Objective A.20.2 Reference to standards A.20.3 Procedure A.20.4 Accetance criteria$ Annex B (normative) Pressure transducers B.1 Scoe B.2 Rated oerating conditions B.2.1 Secified measurement range for ressure

7 B.2.2 Environmental class B.2.3 Power suly B.3 Construction requirements B.3.1 General B.3.2 Casings B.3.3 Indications B.4 Performances B.4.1 Reference conditions B.4.2 Rated oerating conditions B.4.3 Maximum ermissible errors B.4.4 Influence factors B.4.5 Disturbances B.4.6 Durability B.5 Tests of conformity B.5.1 Test conditions B.5.2 Tests B.5.3 Samle of ressure transducers required for testing B.6 Marking Annex C (normative) Platinum resistance thermometer sensors C.1 Scoe C.2 Oerating rated conditions C.2.1 Secified measurement range for temerature C.2.2 Environmental class C.3 Construction requirements C.4 Performances C.5 Marking C.5.1 Required markings C.5.2 Verification mark C.6 Metrological verifications C.6.1 Tye aroval C.6.2 Initial verification C.7 Verification rocedure C.7.1 Visual insection C.7.2 Tye testing (tye aroval) C.7.3 Samles of PRT required for testing C.7.4 Initial verification Annex D (normative) Temerature transducers D.1 Scoe D.2 Rated oerating conditions D.2.1 Secified measurement range for temerature D.2.2 Environmental class D.2.3 Power suly D.3 Construction requirements D.3.1 General D.3.2 Casings D.3.3 Indications D.4 Performances D.4.1 Reference conditions D.4.2 Rated oerating conditions D.4.3 Maximum ermissible errors D.4.4 Influence factors D.4.5 Disturbances D.4.6 Durability D.5 Tests of conformity D.5.1 Test conditions D.5.2 Tests D.5.3 Samle of temerature transducers required for testing D.6 Marking Annex E (informative) Model tye test reort for conversion devices

8 E.1 General E.1.1 General remarks E.1.2 Number of ages E.1.3 Laboratory's identification E.1.4 Alicant E.1.5 Identification of device(s) submitted for testing E.2 Accuracy tests under reference conditions E.2.1 Ambient temerature during the test E.2.2 Test equiment used E.2.3 Test results E.3 Ambient temerature E.3.1 Effect of dry heat E.3.2 Effect of cold E.4 Effect of dam heat, steady state test E.4.1 Ambient temerature during the test E.4.2 Test equiment used E.4.3 Test results E.5 Effect of dam heat, cyclic test E.5.1 Ambient temerature during the test E.5.2 Test equiment used E.5.3 Test results E.6 Electrical ower variation E.6.1 AC ower suly E.6.2 DC ower suly or battery suly E.7 Short time ower reductions E.7.1 Test equiment used E.7.2 Test results E.8 Electrical bursts E.8.1 Test equiment used E.8.2 Test results E.9 Electromagnetic immunity E.9.1 Test equiment used E.9.2 Test results E.10 Electrostatic discharges E.10.1 Test equiment used E.10.2 Test results E.11 Effect of an overload of static ressure E.11.1 Ambient temerature during the test E.11.2 Test equiment used E.11.3 Test results E.12 Effect of vibrations E.12.1 Ambient temerature during the test E.12.2 Test equiment used E.12.3 Test results E.13 Effect of shocks E.13.1 Ambient temerature during the test E.13.2 Test equiment used E.13.3 Test results E.14 Mechanical resistance to overload of static ressure E.14.1 Ambient temerature during the test E.14.2 Test equiment used E.14.3 Test results E.15 Durability E.15.1 Ambient temerature during the test E.15.2 Test equiment used E.15.3 Test equiment used E.16!Alarms oeration E.16.1 Ambient temerature during the test E.16.2 Test equiment used E.16.3 Test results E.17 Reeatability"

9 E.18 #Short time DC ower variations E.18.1 Test equiment used E.18.2 Test results$ E.19 #Surges on suly lines and/or signal lines E.19.1 Test equiment used E.19.2 Test results$ E.20 #Power frequency magnetic field E.20.1 Test equiment used E.20.2 Test results$ Annex F (informative) Model tye test reort for associated transducers F.1 General F.1.1 General remarks F.1.2 Number of ages F.1.3 Laboratory's identification F.1.4 Alicant F.1.5 Identification of device(s) submitted for testing F.2 Accuracy tests under reference conditions F.2.1 Ambient temerature during the test F.2.2 Test equiment used F.2.3 Test results F.3 Ambient temerature F.3.1 Effect of dry heat F.3.2 Effect of cold F.4 Effect of dam heat, steady state test F.4.1 Ambient temerature during the test F.4.2 Test equiment used F.4.3 Test results F.5 Effect of dam heat, cyclic test F.5.1 Ambient temerature during the test F.5.2 Test equiment used F.5.3 Test results F.6 Electrical ower variation F.6.1 AC ower suly F.6.2 DC ower suly or battery suly F.7 Short time ower reductions F.7.1 Ambient temerature during the test F.7.2 Test equiment used F.7.3 Test results F.8 Electrical bursts F.8.1 Ambient temerature during the test F.8.2 Test equiment used F.8.3 Test results F.9 Electromagnetic immunity F.9.1 Ambient temerature during the test F.9.2 Test equiment used F.9.3 Test results F.10 Electrostatic discharges F.10.1 Ambient temerature during the test F.10.2 Test equiment used F.10.3 Test results F.11 Effect of an overload of static ressure F.11.1 Ambient temerature during the test F.11.2 Test equiment used F.11.3 Test results F.12 Effect of vibrations F.12.1 Ambient temerature during the test F.12.2 Test equiment used F.12.3 Test results F.13 Effect of shocks F.13.1 Ambient temerature during the test

10 F.13.2 Test equiment used F.13.3 Test results F.14 Mechanical resistance to overload of static ressure F.14.1 Ambient temerature during the test F.14.2 Test equiment used F.14.3 Test results F.15 Durability F.15.1 Ambient temerature during the test F.15.2 Test equiment used F.15.3 Test results F.16!Reeatability" Annex ZA (informative)!relationshi between this Euroean Standard and the Essential Requirements of EU Directive 2004/22 Measuring Instruments Directive" Bibliograhy

11 Foreword!This document #(EN :2005+A2:2010)$ has been reared by Technical Committee CEN/TC 237 Gas meters, the secretariat of which is held by BSI. This #deleted text$ Euroean Standard #deleted text$ shall be given the status of a national standard, either by ublication of an identical text or by endorsement, at the latest by #Aril 2011$, and conflicting national standards shall be withdrawn at the latest by #Aril 2011$. This document has been reared under a mandate given to CEN by the Euroean Commission and the Euroean Free Trade Association, and suorts essential requirements of EU Directive 2004/22 Measuring Instruments Directive (MID). For relationshi with EU Directive 2004/22, see informative Annex ZA, which is an integral art of this document." This document includes Amendment 1, aroved by CEN on and Amendment 2, aroved by CEN on This document suersedes #EN :2005$. The start and finish of text introduced or altered by amendment is indicated in the text by tags! " and # $ Attention is drawn to the ossibility that some of the elements of this document may be the subject of atent rights. CEN [and/or CENELEC] shall not be held resonsible for identifying any or all such atent rights. Due to technical develoments the layout of the document has been changed and EN will aear in arts: Part 1: Volume conversion (this Euroean Standard), Part 2: Energy conversion (in rearation), Part 3: Data loggers. Further arts are under consideration, following the technical rogress. In the rearation of this Euroean Standard, the content of OIML Publication, International Document 11, International Recommendations 6 and International Recommendations 32 and the content of member bodies' national standards on gas-volume electronic conversion devices have been taken into account.!deleted text" According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to imlement this Euroean Standard: Austria, Belgium, Bulgaria, Croatia, Cyrus, Czech Reublic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Sain, Sweden, Switzerland and United Kingdom. 9

12 1 Scoe This Euroean Standard secifies the requirements and tests for the construction, erformance, safety and conformity of gas-volume electronic conversion devices associated to gas meters, used to measure volumes of fuel gases of the 1st and 2nd families according to EN 437. This Euroean Standard is intended for tye testing, the detailed relevant rovisions of which are given in Annex A. Only three kinds of conversion are treated in this Euroean Standard: conversion as a function of temerature only (called T conversion); conversion as a function of the ressure and of the temerature with constant comression factor (called PT conversion); conversion as a function of the ressure, the temerature and taking into account the comression factor (called PTZ conversion).!this document is not relevant to temerature conversion integrated into gas meters which only indicate the converted volume." EN for energy conversion is in rearation. Gas-volume conversion devices consist of a calculator and a temerature transducer or a calculator, a temerature transducer and a ressure transducer locally installed. For alication of this Euroean Standard, a conversion device may be, as a choice of the manufacturer, considered as a comlete instrument (Tye 1) or made of searate elements (Tye 2), according to the definitions given in and In this last case, the rovisions concerning ressure transducers, temerature sensors and temerature transducers are given in Annexes B, C and D resectively. Any conversion device can rovide an error curve correction for a gas meter. NOTE When rendering an account to an end user the readings from the conversion device can be used in conjunction with the readings from a gas meter conforming to EN 1359, EN 12480, or EN 12261, as aroriate, or to any other aroriate and relevant international or national standard for gas meters, without rejudice of national regulations. 2 Normative references The following referenced documents are indisensable for the alication of this Euroean Standard. For dated references, only the edition cited alies. For undated references, the latest edition of the referenced document (including any amendments) alies. EN 437, Test gases Test ressures Aliance categories EN 1776, Gas suly systems Natural gas measuring stations Functional requirements #deleted text$ EN 55011, Industrial, scientific and medical (ISM) radio-frequency equiment Radio disturbance characteristics Limits and methods of measurement (CISPR 11:1997, modified) EN , Environmental testing Part 2: Tests Tests A: Cold (IEC :1990) 10

13 EN , Basic environmental testing rocedures Part 2: Tests Tests B: Dry heat (IEC : IEC A:1976) EN , Environmental testing Part 2: Tests Test Db and guidance: Dam heat, cyclic ( hour cycle) (IEC : A1:1985) EN , Basic environmental testing rocedures Part 2: Tests Test Ec: Dro and tole, rimarily for equiment-tye secimens (IEC : A1:1982) EN , Environmental testing Part 2-78: Tests Test Cab: Dam heat, steady state (IEC :2001) EN , Electrical aaratus for otentially exlosive atmosheres Part 0: General requirements (IEC :2004) EN , Electrical aaratus for otentially exlosive atmosheres Flameroof enclosures "d" (IEC :2003) EN , Electrical aaratus for otentially exlosive atmosheres Part 2: Pressurized aaratus "" (IEC :2001) #EN , Exlosive atmosheres Part 5: Equiment rotection by owder filling "q" (IEC :2007) EN , Exlosive atmosheres Part 6: Equiment rotection by oil immersion "o" (IEC :2007)$ EN , Electrical aaratus for otentially exlosive atmosheres Increased safety "e" (IEC :2001) #EN , Exlosive atmosheres Part 11: Equiment rotection by intrinsic safety "i" (IEC :2006) EN , Electrical aaratus for exlosive gas atmosheres Part 25: Intrinsically safe systems (IEC :2003)$ EN 60529, Degrees of rotection rovided by enclosures (IP code) (IEC 60529:1989)!EN :2000, Automatic electrical controls for household and similar use Part 1: General requirements (IEC :1999, modified)" EN 60751, Industrial latinum resistance thermometer sensors (IEC 60751: A1:1986) EN , Information technology equiment Safety Part 1: General requirements (IEC :2001, modified) EN , Electromagnetic comatibility (EMC) Part 4: Testing and measurement techniques Section 2: Electrostatic discharge immunity test Basic EMC ublication (IEC :1995) EN , Electromagnetic comatibility (EMC) Part 4-3: Testing and measurement techniques Radiated, radio-frequency, electromagnetic field immunity test (IEC :2002) EN , Electromagnetic comatibility (EMC) Part 4-4: Testing and measurement techniques Electrical fast transient/burst immunity test (IEC :2004) #EN , Electromagnetic comatibility (EMC) Part 4-5: Testing and measurement techniques Surge immunity test (IEC :2005)$ EN , Electromagnetic comatibility (EMC) Part 4: Testing and measurement techniques Section 6: Immunity to conducted disturbances, induced by radio-frequency fields (IEC :1996) 11

14 #EN , Electromagnetic comatibility (EMC) Part 4: Testing and measurement techniques Section 8: Power frequency magnetic field immunity test (IEC : A1 2001)$ EN , Electromagnetic comatibility (EMC) Part 4-11: Testing and measurement techniques Voltage dis, short interrutions and voltage variations immunity tests (IEC :2004) #EN , Electromagnetic Comatibility (EMC) Part 4-29: Testing and measurement techniques Voltage dis, short interrutions and voltage variations on d.c. inut ower ort immunity tests (IEC :2000)$ EN ISO :2005, Natural gas Calculation of comression factor Part 2: Calculation using molarcomosition analysis (ISO :1997) EN ISO :2005, Natural gas Calculation of comression factor Part 3: Calculation using hysical roerties (ISO :1997) 3 Terms, definitions and symbols 3.1 Terms and definitions For the uroses of this Euroean Standard, the following terms and definitions aly absolute static ressure value of the static ressure of the gas relative to vacuum!3.1.2 base conditions secified conditions to which the measured quantity of gas is converted" EXAMPLES Temerature of 273,15 K and absolute ressure of 1, bar 1 or temerature of 288,15 K and absolute ressure of 1, bar calculator electronic device that receives the outut signals from the associated gas meter and transducers and rocesses them conversion factor factor equal to the volume at base conditions divided by the corrected volume, or if there is no gas meter correction, equal to the volume at base conditions divided by the volume at measurement conditions conventional true value (of a quantity) value attributed to a articular quantity and acceted, sometimes by convention, as having an uncertainty aroriate for a given urose corrected volume volume at measurement conditions corrected for the error curve of the gas meter correction value added algebraically to the uncorrected result of a measurement to correct the systematic error 12

15 3.1.8 correction factor numerical factor by which the measured volume is multilied to correct it to comensate the error curve of the gas meter dislay element or assembly of elements of the indicating device on which the results of measurement and memorized values are dislayed disturbance influence quantity having a value within the limits secified but outside the secified rated oerating conditions of the measuring instrument NOTE An influence quantity is a disturbance if the rated oerating conditions for that influence quantity are not secified durability ability of an instrument to maintain its erformance characteristics over a secified eriod of use environmental class class referring to the ambient temerature, humidity and ower suly error of conversion difference between the conversion factor C dislayed by a conversion device and the conventional true value of the conversation factor C CV, exressed as a ercentage of the conventional true value of the conversion factor error of indication indication of a measuring instrument minus the (conventional) true value of the corresonding inut quantity error of the calculator unit error of the indicated volume at base conditions V b, when the gas volume, ressure and temerature are by signals, in accordance to the manufacturer secification of interfaces NOTE The calculator error includes all conversion errors with the excetion of the ressure and temerature transducer errors (i.e. signal conditioning, Z factor calculation (if alicable), other mathematical calculations etc.) error of the ressure transducer difference between the measured outut signals from the ressure transducer and the nominal signal at the alied hysical value error of the temerature transducer difference between the measured outut signals from the temerature transducer and the nominal signal at the alied hysical value gas-volume conversion device device that comutes, integrates and indicates the volume increments measured by a gas meter if it were oerating at base conditions, using as inuts the volume at measurement conditions as measured by the gas meter, and other arameters such as gas temerature and gas ressure NOTE 1 The conversion device can also comensate for the error curve of a gas meter and associated measuring transducers. 13

16 NOTE 2 The deviation from the ideal gas law can be comensated by the comression factor gas volume conversion device tye 1 (comlete system) conversion device with secific tyes of transducers for ressure and temerature or for temerature only gas volume conversion device tye 2 (searate comonent) conversion device with external searate transducers for ressure and temerature or for temerature only and for searate calculator, which may be aroved searately NOTE The matching of the various elements constituting a conversion device tye 2 is subjected to verification indicating device art of a measuring instrument that dislays an indication (alhanumeric string) influence factor influence quantity having a value within the secified rated oerating conditions of the measuring instrument influence quantity quantity that is not a measurand but that affects the result of the measurement (e.g. ambient temerature) intrinsic error error of a measuring instrument, determined under reference conditions maximum oerating ressure MOP maximum ressure at which a system can be oerated continuously under normal conditions NOTE Normal conditions are: no fault in any device or stream measurement conditions conditions of the gas, the volume of which is measured at the oint of measurement (e.g. the temerature and the ressure of the gas) measuring transducer device that rovides an outut quantity having a determined relationshi to the inut quantity overressure maximum static ressure to which the transducer may be submitted without durable alteration of its metrological characteristics : it is set in accordance with the maximum allowable ressure! rated oerating conditions values for the measurand and influence quantities making u the normal working conditions of an instrument"!deleted text" reference conditions condition of use rescribed for testing the erformance of a measuring instrument or for inter-comarison of results of measurements 14

17 sensor element of a measuring instrument or measuring chain that is directly affected by the measurand secified measuring range of transducers set of values of measurands (the ressure for the ressure transducer or temerature for the temerature transducer) for which the errors of the conversion device are intended to lie within the limits secified in this Euroean Standard NOTE The uer and lower limits of the secified measuring range are called maximum value and minimum value resectively. EXAMPLE maximum absolute ressure: 12 bar; minimum absolute ressure: 4 bar secified field of measurement of a conversion device set of values at measurement conditions for which the errors of the conversion device are within secified limits NOTE 1 A conversion device has a measuring range for every quantity that it rocesses. NOTE 2 The secified field of measurement alies to the characteristic quantities of the gas that are used to determine the conversion factor static gauge ressure value of the static ressure of the gas relative to the ambient atmosheric ressure uncertainty of measurement arameter, associated with the result of a measurement, that characterizes the disersion of the values that could reasonably be attributed to the measurand volume volume without secifying whether it is a corrected volume at measurement conditions or an uncorrected volume at measurement conditions! measurand articular quantity subject to measurement critical change value value at which the change in the measurement result is considered undesirable" 3.2 Symbols The symbols used in this Euroean Standard are listed in Table 1. 15

18 Table 1 Symbols Symbols Reresented quantity Units V volume : V m or V c m 3 V m volume at measurement conditions m 3 V c corrected volume (gas meter error) m 3 V b volume at base conditions m 3 V CV conventional true value of the volume m 3 C conversion factor - C c calculator conversion - C f correction factor - C CV conventional true value of the conversion factor - f(q) correction function - K or K' coefficients - absolute ressure at measurement conditions bar or MPa b absolute ressure at base conditions bar or MPa g gauge ressure bar or MPa CV conventional true value of the absolute ressure bar or MPa T absolute temerature at measurement conditions K T b absolute temerature at base conditions K T min minimum absolute temerature K T max maximum absolute temerature K T CV conventional true value of the absolute temerature K Z comression factor of the gas at measurement conditions - Z b comression factor of the gas at base conditions - Z CV conventional true value of the comression factor - atm atmosheric ressure bar or MPa max maximum absolute gas ressure bar or MPa min minimum absolute gas ressure bar or MPa Q flowrate m 3 /h Q max maximum flowrate m 3 /h Q min minimum flowrate m 3 /h t am ambient temerature C t am,max maximum ambient temerature C t am,min minimum ambient temerature C t gas temerature C t max maximum gas temerature C t min minimum gas temerature C U nom nominal suly voltage V f nom nominal suly frequency Hz e total conversion factor error % e f error on the calculation of conversion factor % e error on the ressure measurement % e t error on the temerature measurement % e c error on the conversion factor % e v error on the converted volume % 16

19 3.3!Classification Mechanical classes M1 This class alies to instruments used in locations with vibration and shocks of low significance, e.g. for instruments fastened to light suorting structures subject to negligible vibrations and shocks transmitted from local blasting or ile-driving activities, slamming doors, etc. M2 This class alies to instruments used in locations with significant or high levels of vibration and shock, e.g. transmitted from machines and assing vehicles in the vicinity or adjacent to heavy machines, conveyor belts, etc Electromagnetic environmental classes E1 This class alies to instruments used in locations with electromagnetic disturbances corresonding to those likely to be found in residential, commercial and light industrial buildings. E2 This class alies to instruments used in locations with electromagnetic disturbances corresonding to those likely to be found in other industrial buildings." 4 Princile of measurement 4.1 Conversion as a function of temerature In this case the conversion device consists of a calculator and a temerature transducer and it converts the volume to the base conditions. The ressure is not measured, but may be included as a fixed value in the rocessing of the conversion factor. The comression factor is not, but may be included as a fixed value in the rocessing of the conversion factor. The error of a gas volume conversion device, measuring only temerature, is referring to the reference conversion factor as taking into account the comression factor at a fixed set ressure and measured temerature. The volume at base conditions is obtained from the relationshi: V = C V b C is the conversion factor given from the relationshi: C = K T K is a fixed value obtained from the relationshi: K = b Zb Tb Z 4.2 Conversion as a function of ressure and temerature In this case, the conversion device consists of a calculator, a ressure transducer and a temerature transducer. 17

20 The comression factor may be considered as a fixed value from mean measurement conditions and a determined gas comosition. The volume at base conditions is obtained by the relationshi: V b = C V C is the conversion factor given from the relationshi: C = K' T K is a fixed value obtained from the relationshi: K' = 1 b Zb Tb Z An absolute ressure transducer shall be used for absolute ressures below 21 bar. For absolute ressures equal to or greater than 21 bar a gauge ressure transducer may be used. In this case the value of the atmosheric ressure shall be the average value taking into account the altitude of the installation site. This value shall be reset. 4.3 Conversion as a function of ressure, temerature and deviation from the ideal gas law In this case, the conversion device consists of a calculator, a ressure transducer and a temerature transducer. The general requirements indicated in 4.2 shall be enforced. The deviation from the ideal gas law is comensated by the calculation of the comression factor using an aroriate equation as a function of ressure and temerature: Z = f(,t) Settable gas roerties and comonents inuts are used for the comression factor calculation. The volume at base conditions is obtained from the relationshi: V b = C V C is the conversion factor given by the relationshi: C = b Tb Zb T Z The manufacturer shall secify the method used for comression factor calculation. An absolute ressure transducer shall be used for absolute ressures below 21 bar. For absolute ressures equal to or greater than 21 bar, a gauge ressure transducer may be used. In this case, the value of the atmosheric ressure shall be the average value taking into account the altitude of the installation site. This value shall be reset. 18

21 4.4 Correction of the volume at measurement conditions The object of the correction function is to comensate the error of the gas meter, as determined in the calibration certificate. The conversion device may be able (otionally) to correct the error of the gas meter. When using this otion it shall be ensured that the error curve to be used is relevant to the actual oerational conditions. If this correction is available, it shall be integrated in the configurations stated in 4.1, 4.2 and 4.3; in those cases, the volume marked as V means V c. The correction function of the conversion device shall be able to correct deviations recorded when calibrating the gas meter to which it is connected. The error of the meter will be corrected by the use of a function f(q) in such a way that for each oerating oint: Vc = Vm f(q) The manufacturer shall secify the method used. If a non-linear interolation between the calibration oints is used, the manufacturer shall rovide roof that the method has a better weighted (by flow) accuracy than the linear interolation. The choice of the arameters shall be so that the correction function f(q) remains, at all oints, definite, continuous and derivable for rates of flow between Q min and Q max. The correction can only be alied if the gas meter roduces at least 10 ulses er second at Q min. Below Q min no correction is allowed and above Q max, the correction factor shall remain at the value obtained at Q max. 5 Rated oerating conditions 5.1 Secified field of measurement The field of measurement of the comlete instrument shall be secified by the manufacturer Secified measurement range for gas ressure The transducer shall be calibrated over the range secified by the manufacturer which shall be at least: max min > Secified measurement range for gas temerature The manufacturer shall secify the gas temerature range according to the following: normal range: -20 C to +50 C; limited range: a minimum range of 40 C anywhere between the limits of the normal range; extended range: to be secified by the manufacturer. 19

22 5.1.3 Gas characteristics Fuel gases of the first and second families according to EN 437.!The manufacturer shall indicate the: gas family or grou; maximum oerating ressure." 5.1.4!Base conditions The manufacturer shall secify the base conditions, or range of base conditions for converted quantities." 5.2!Environmental conditions" Ambient temerature range!the manufacturer shall secify the ambient temerature range of the gas-volume conversion device with a minimum temerature range of 50 C for the climatic environment, and the minimum temerature limit being either -40 C, -25 C, -10 C or 5 C, and the maximum temerature limit being either 30 C, 40 C, 55 C or 70 C." Humidity range The instrument shall oerate in a relative humidity range of 10 % to 93 %.!The manufacturer shall indicate whether the instrument is designed for condensing or non-condensing humidity as well as the intended location for the instrument. If designed for non-condensing humidity, the device shall meet the requirements of Test A.4. If designed for condensing humidity, the device shall meet the requirements of Test A.5." 5.2.3!Mechanical environment The manufacturer shall secify the mechanical class for which the device is intended (M1 or M2) (see 3.3.1) Electromagnetic environment The device shall be able to oerate under electromagnetic environmental class E2 (see 3.3.2)." 5.3 Power suly!the manufacturer shall secify the nominal value of the AC suly and/or the limits of DC suly. The limits of DC suly shall be comatible with customers' requirements and/or the electricity suly of country of destination." 6 Construction requirements 6.1 General All the constituent elements of a gas-volume conversion device shall be constructed of materials having aroriate quality to resist the various forms of degradation which may occur under normal oerating conditions as secified by the manufacturer. A gas-volume conversion device shall, in all circumstances, withstand the influence factors and disturbances defined!in 8.5". 20

23 6.1.2 All the constituent elements of a gas-volume conversion device shall be designed in such a way that it does not degrade the accuracy of the measurement of the gas meter with which it is associated The gas-volume conversion device shall be constructed in such a way that any intervention, liable to influence the results of measurement, shall cause ermanently visible damage to the conversion device or its rotective seals, or set an alarm which shall be memorized in the event register. The seals shall be visibly fixed, and easily accessible. Electronic seals shall comly with the following requirements: access shall only be obtained by using a assword or a code!that can be udated or by using a secific device"; the last intervention, at least, shall be registered in the memory, including date and time of intervention and a secific element to identify the intervention; It shall be ossible to have access to the intervention(s) registered in the memory. For gas volume conversion devices, where the given inuts may be dismantled or relaced, all connections and interfaces between the calculator and transducers or meter should be rotected by searate seals to avoid the breaking of the main metrological seal in case of comonent relacement. Access to arameters which take art in the determination of the measured results or to the measured results themselves shall not be ossible through the disconnected oints, excet if the conditions given in this aragrah are fulfilled The conversion factor shall be re at intervals between the volume ulses not exceeding 1 min for a temerature conversion device and at intervals not exceeding 30 s for the other tyes of gas-volume conversion devices. However, when no volume signal has been received from the gas meter for: over 1 min for a temerature conversion device; or over 30 s for other tyes, recalculation is not required until the next volume signal is received Any interfaces and connections fitted within the conversion device allowing the connection of comlementary devices shall not corrut the metrological behaviour of the conversion device The interconnections and any interfaces between the calculator and the transducers are integral arts of the conversion device. The manufacturer shall secify the length and characteristics of the interconnections and of any interfaces where these may affect the accuracy of measurement of the gas-volume conversion device Equiment used in hazardous areas shall meet the electrical requirements secified in the aroriate standards: #EN , EN , EN , EN , EN , EN , EN and EN $ All the constituent elements of a conversion device shall be constructed in such a way that the comatibility of electromagnetic disturbances conforms the requirements secified in EN Casings shall meet the requirements concerning the security of the equiment as secified in EN Casings The casings of all the constituent elements of a conversion device shall have an ingress rotection index (IP), secified in EN 60529, comlying with the installation conditions secified by the manufacturer. --``,,````,,,``,`,,`,,,,``,`,,,,-`-`,,`,,` 21

24 Any art of the conversion device designed for outdoor use and not intended to be installed in a weatherroof housing shall be at least in accordance with the severity level IP 65, secified in EN Indications General The calculator shall be fitted with an indicating device that indicates: the incremented volume at base conditions V b ; the incremented volume at measurement conditions V m ; the incremented corrected volume V c if alicable; the alarms' indications as defined in Additionally, the following information shall be indicated by a method described in :! the base conditions in the form: 22 T b =. K; b =. bar;" the conversion factor C; the comression factor Z if alicable; the arameter values measured by the transducers (e.g. ressure in bar, temerature t in C); the correction factor C f if alicable; the correction function f(q) if alicable; alarm(s) indication(s) additional to those defined in 6.6 if alicable; the entered data which affect the metrological result; gas roerties used in Z comutation if alicable; the reference to the method by which the comression factor is or the constant, if alicable; the serial number of the transducers as aroriate; the uer and the lower limits of the secified measuring range of the temerature transducer in K or C and the gauge or absolute ressure, in bar, of the ressure transducer as aroriate; the value of one volumetric ulse at measurement conditions in the form: 1 im = ) m 3 (or dm 3 ); or 1 m 3 (or dm 3 ) = ) im; the arameters for gas meter error correction curve if alicable;

25 the indication of the end of life of the battery, if alicable;! the software version." It shall also be ossible, at the time of the control oerations described in Annex A, to dislay the values of the conversion factor and of the various quantities measured or The information shown in shall be indicated either on: the indicating device of the gas volume conversion device; a ermanently attached information late with indelible markings; an external attached indicating device; a combination of the above The volume at base conditions shall be referentially dislayed The method by which the quantities described in may be dislayed on the indicating device of the gas volume conversion device shall take one of the following forms: by means of direct oerator inut (e.g. the deression of ush buttons, whereby each quantity may be selected by sequential oerator inuts or combination of oerator inuts. Each oerator inut shall select the current value of the quantity. If after 255 s there has been no oerator inut, the dislay shall revert to showing the volume at base conditions, or to visualising V b by a simle oeration (e.g. the deression of a ush button); by means of automatic and sequential scrolling through the quantities that may be continuous, or initiated by an oerator inut. In this case the dislay shall show each arameter for 5 s and the volume at base conditions shall be shown every 15 s The identification and the unit of each quantity or arameter that can be indicated shall be clearly shown next to or uon the dislay unit of the calculator. EXAMPLE Volume at base conditions, V b, m The scale interval of the dislay of the volume at base conditions shall be of the form 10 n units of volume. The value of the scale interval shall be clearly stated in the vicinity where the volume at base conditions is dislayed The indicating device shall have at least 8 significant digits Electronic indicating device The device indicating the volume at base conditions shall be rovided with means for checking to ensure that the dislay is oerating correctly The minimum height of the numerals for the dislay of converted volume V b shall be 4 mm and the minimum width shall be 2,4 mm It shall be ossible to read the index clearly and correctly, within an angle of 15 from normal to the window When all the digits of the indicating device are not used for the indication of the volume, every unused digit to the left of the significant digit shall indicate zero. 23

26 6.4 Inuts for volume conversion The volume conversion device shall have an inut that shall be able to rocess a signal from the associated gas meter. The inut shall resond to every ulse in such a manner that no ulses are gained or lost by the volume conversion device. The manufacturer shall secify the ulse inut characteristic of the gas volume conversion device and the maximum frequency. For a conversion device tye 2, the interfaces between the calculator unit and the transducer shall be secified in terms of all arameters that may influence that measurement. NOTE Meters can often be subject to considerable eriods of time where there is no gas flow. During such eriods, conventional LF and HF ulse oututs will, in effect, be oerating at 0 Hz. Conversely, at maximum throughut, a tyical meter's LF outut could rise to 2 Hz and its HF outut u to 5 khz or higher. Any ulse inut circuitry in a volume conversion device will have to be caable of dealing with such frequency ranges. 6.5 Battery owered conversion device All the constituent elements of the conversion device owered by (a) relaceable battery(ies) shall work!for a minimum of five years" without relacing the battery(ies) under the following conditions: maximum of all frequency inuts; t amb,min ; max and T min. The manufacturer shall indicate the estimated life time of the battery in the above conditions. The manufacturer shall secify the tye of the battery and whether the battery can be changed in a hazardous area and if so, under which conditions. NOTE These conditions do not take into account the consumtion!from any outut and communication orts". The battery comartment should make rovisions to revent unauthorised access. Batteries shall be relaced only after the breaking of a seal different from the metrological seal An indication shall be rovided when 10 %, or less, of the life, or estimated life of the battery is remaining. When the estimated life is, the calculation shall be done taking into account the actual oerating conditions secified by the manufacturer of the conversion device A battery exchange (if the battery is relaceable) shall be ossible without breaking any metrological seals of the conversion device. During the battery exchange the following information shall be retained: the volume at base conditions; the volume at measurement conditions; the corrected volume if alicable; the alarms indications; the entered data which affect the metrological results; the last intervention, at least, as secified in