1、April 2016 English price group 28No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 91.140.40!%Q:“2469723www.din.deDIN
2、 EN 12405-3Gas meters Conversion devices Part 3: Flow computer;English version EN 12405-3:2015,English translation of DIN EN 12405-3:2016-04Gaszhler Umwerter Teil 3: Flowcomputer;Englische Fassung EN 12405-3:2015,Englische bersetzung von DIN EN 12405-3:2016-04Compteurs de gaz Dispositifs de conversi
3、on Partie 3: Calculateurs de dbit;Version anglaise EN 12405-3:2015,Traduction anglaise de DIN EN 12405-3:2016-04www.beuth.deDocument comprises 79 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.This standard has been included i
4、n the body of technical rules and standards for gas issued by the DVGW Deutscher Verein des Gas- und Wasserfaches e.V. (German Technical and Scientific Association for Gas and Water). 04.16 DIN EN 12405-3:2016-04 2 A comma is used as the decimal marker. National foreword This document (EN 12405-3:20
5、15) has been prepared by Technical Committee CEN/TC 237 “Gas meters” (Secretariat: BSI, United Kingdom). The responsible German body involved in its preparation was DIN-Normenausschuss Gastechnik (DIN Standards Committee Gas Technology), Working Committee NA 032-02-05 AA Gasmessung. EN 12405 Gas met
6、ers Conversion devices consists of the following parts: Part 1: Volume conversion (and its amendments EN 12404-1:2005/A1:2006 and EN 12405-1:2005+A2:2010 to allow the harmonization of the standard with the Measuring Instruments Directive 2004/22/EC) Part 2: Energy conversion Part 3: Flow computer In
7、 the preparation of this European Standard, the content of OIML Publication “Recommendation 140 measuring systems for gaseous fuel” has been taken into account. This standard specifies the requirements and tests for the construction, performance, safety and conformity of flow computers (FCs) used to
8、 meet the metrological and technical requirements of a high accuracy volume conversion device. In the context of this standard, a differentiation is made between signal acquisition functions, sensor functions and metering functions to achieve data processing. It is intended to include this standard
9、in the body of technical rules and standards for gas issued by the DVGW Deutscher Verein des Gas- und Wasserfaches e.V. (German Technical and Scientific Association for Gas and Water). EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12405-3 December 2015 ICS 91.140.40 English Version Gas meters
10、 - Conversion devices - Part 3: Flow computer Compteurs de gaz - Dispositifs de conversion - Partie 3: Calculateurs de dbit Gaszhler - Umwerter - Teil 3: Flowcomputer This European Standard was approved by CEN on 19 September 2015. CEN members are bound to comply with the CEN/CENELEC Internal Regula
11、tions which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member
12、. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN
13、 members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, P
14、ortugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any
15、 form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12405-3:2015 EEN 12405-3:2015 (E) 2 Contents Page European foreword . 5 Introduction 6 1 Scope 8 2 Normative references 8 3 Terms, definitions and symbols 10 3.1 Terms and definitions 10 3.2 Symbols and subscripts . 16 3
16、.3 Abbreviations 18 3.4 Environmental classification for flow computers 18 3.4.1 Climatic conditions 18 3.4.2 Mechanical conditions 18 3.4.3 Electrical and Electromagnetic conditions . 18 4 Principle of measurement 18 4.1 General . 18 4.2 Correction functions . 19 4.2.1 General . 19 4.2.2 Correction
17、 of the volume at measurement conditions . 20 4.2.3 Temperature and pressure correction of USM body dimension . 23 4.2.4 Temperature and pressure measurement correction for conversion . 23 5 Rated operating conditions 23 5.1 Specified field of measurement . 23 5.1.1 General . 23 5.1.2 Specified meas
18、urement range for gas pressure 23 5.1.3 Specified measurement range for gas temperature 24 5.1.4 Gas characteristics . 24 5.1.5 Base conditions . 24 5.2 Environmental conditions 24 5.2.1 Ambient temperature range 24 5.2.2 Humidity range . 24 5.3 Power supply . 24 6 Construction requirements 25 6.1 G
19、eneral . 25 6.2 Sealing 25 6.3 Time measuring functions 27 6.3.1 Clock 27 6.3.2 Time interval . 27 6.4 Casings . 28 6.5 Indications 28 6.5.1 General . 28 6.5.2 Electronic indicating device . 30 6.6 Inputs for volume conversion 30 6.7 Alarms in flow computer . 31 6.7.1 Detection of defective operatio
20、n situations . 31 DIN EN 12405-3:2016-04EN 12405-3:2015 (E) 3 6.7.2 Handling of volumes during maintenance 31 6.7.3 Memorization of metrological data 31 6.7.4 Handling of alarms . 31 6.8 Specific monitoring functions performed by flow computer 31 6.8.1 General . 31 6.8.2 Turbine Meter health check (
21、Mechanical meter) . 33 6.8.3 USM health check (meter integrity check) 34 6.8.4 Gas analysis devices health check 35 6.8.5 p-T transducer health check . 36 6.8.6 Self check of the Z algorithm . 36 6.8.7 Volume comparison . 36 6.8.8 Gas quality comparison 38 6.9 Cut-off function 38 6.10 Long-term data
22、 storage 38 6.10.1 General . 38 6.10.2 Categories of data to be stored 39 6.10.3 Triggers and methods for storage 39 6.10.4 Clock-time stamps 40 6.10.5 Security (physical, electronic and software) 40 6.10.6 Error handling . 41 6.10.7 Long term data storage Security audit . 41 7 Installation requirem
23、ents . 42 7.1 General . 42 7.2 Calculator. 43 7.3 Temperature transducer . 43 7.4 Pressure transducer 43 8 Performance . 44 8.1 Reference conditions . 44 8.2 Rated operating conditions . 44 8.3 Maximum permissible errors. 44 8.3.1 General . 44 8.3.2 Global approach: error of main indication 45 8.3.3
24、 Modular approach: specific errors for a FC . 45 8.4 Conditions of matching the constituent elements of a FC 45 8.5 Influence factors . 46 8.6 Disturbances . 46 8.7 Durability. 46 8.8 Repeatability 46 8.9 Reliability 46 8.10 Adjustment and calibration of the transducers . 47 9 Tests of conformity 47
25、 9.1 Verification of the construction requirements 47 9.2 Verification of the performance requirements . 48 9.2.1 Test conditions 48 9.2.2 Samples of FC required for testing . 49 10 Marking 50 11 Installation and operating instructions . 51 Annex A (normative) Type test 52 A.1 General conditions . 5
26、2 A.2 Accuracy tests under reference conditions . 54 DIN EN 12405-3:2016-04EN 12405-3:2015 (E) 4 A.3 Effect of ambient temperature 55 A.4 Effect of damp heat, steady-state test . 55 A.5 Effect of damp heat, cyclic test . 56 A.6 Electrical power variation 56 A.7 Short time power reductions . 57 A.8 E
27、lectrical bursts 58 A.9 Electromagnetic susceptibility 58 A.10 Electrostatic discharges . 59 A.11 Overload of pressure (only for pressure transducers) 59 A.12 Effect of vibrations . 60 A.13 Effect of shocks 60 A.14 Overload of pressure (mechanical) (only for pressure transducer) . 61 A.15 Durability
28、 61 A.16 Alarms operation . 62 A.17 Repeatability 63 A.18 Short time DC power variations 63 A.19 Surges on supply lines and/or signal lines . 64 A.20 Power frequency magnetic field . 64 Annex B (normative) Pressure transducers . 65 B.1 Scope . 65 B.2 Rated operating conditions 65 B.3 Construction re
29、quirements 65 B.4 Performances 66 B.5 Tests of conformity 67 B.6 Marking 67 Annex C (normative) Temperature transducers . 68 C.1 Scope . 68 C.2 Rated operating conditions 68 C.3 Construction requirements 68 C.4 Performances 69 C.5 Tests of conformity 70 C.6 Marking 70 Annex D (normative) Requirement
30、s and testing of meter error correction . 71 D.1 General . 71 D.2 Verification of the volumetric flow rate determination. 71 D.3 Verification of the gas density calculation procedure 71 D.4 Verification of the gas viscosity calculation procedures . 72 D.5 Verification of the error transposition from
31、 e(Qi) to e(Rei) 72 D.6 Verification of the error function (Q) or (Re) interpolation or approximation 73 D.7 Verification of correction factor F(Q) or F(Re), corrected flow rate and corrected volume determination 73 D.8 Verification of the activation and deactivation of error correction calculations
32、 on limits of its application . 73 Annex E (informative) Range of application of meter error correction with functions: e(Q) or e (Re) 74 E.1 General . 74 E.2 Range of application 74 E.3 Example for turbine meters working at popnearly constant 75 Bibliography . 77 DIN EN 12405-3:2016-04EN 12405-3:20
33、15 (E) 5 European foreword This document (EN 12405-3:2015) has been prepared by Technical Committee CEN/TC 237 “Gas meters”, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement,
34、 at the latest by June 2016, and conflicting national standards shall be withdrawn at the latest by June 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or
35、 all such patent rights. EN 12405 consists of the following parts: Part 1: Volume conversion (and its amendments EN 12405-1:2005/A1:2006 and EN 12405-1:2005+A2:2010 to allow the harmonization of the standard with the Measuring Instruments Directive 2004/22/EC); Part 2: Energy conversion; Part 3: flo
36、w computer (this European Standard). In the preparation of this European Standard, the content of OIML Publication, “Recommendation 140 measuring systems for gaseous fuel”, has been taken into account. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the fol
37、lowing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands,
38、 Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. DIN EN 12405-3:2016-04EN 12405-3:2015 (E) 6 Introduction A high accuracy volume conversion device can be needed depending of the intended use. EN 12405-3 is established in order to meet
39、 severe requirements concerning accuracy and related functions. For the purpose of this European Standard, functions are described, although these functions can be physically located in different components (e.g. calibration curve programmed in the measuring equipment itself or in the calculator). F
40、our main categories of functions are described to achieve data processing: Sensor signal Acquisition functions: to process signals from physical quantity provided by sensors and transducers to measurands; Sensor functions: to convert measurands to correct measurements, mostly based upon calibration
41、results and filtering procedures; Metering functions: to calculate derived values such as volume, calorific value, compression factor etc. based upon international standards and formulas and to take care of the supervision and monitoring for the purpose of high accuracy and substitution values; Long
42、 Term Data Storage functions: to keep all relevant information necessary to construct or reconstruct calculated values: for later legally relevant purposes (e.g. the conclusion of a commercial transaction); for back up of the relevant data. DIN EN 12405-3:2016-04EN 12405-3:2015 (E) 7 Figure 1 Descri
43、ption of the functionalities of the flow computer calculator Modular and global approaches In the modular approach, the flow computer is an assembly of separate associated measuring instruments and a calculator, which are verified separately. Each instrument is verified according to its testing proc
44、edure, using the indication available on the calculator or on the associated measuring instrument itself. In this case, the indication shall correspond to the indication of that measuring instrument, which is directly performing volume conversion. The verification of the functions consists in verify
45、ing the calculation concerning each characteristic quantity of the gas and/or the calculation for the volume conversion. In case of external communication, sufficient resolution of required data is ensured during data transmission. The associated measuring instruments are validated for or with a typ
46、e calculator in order to ensure the interoperability of the association. CVDD is covered in EN 12405-2. In the global approach, the flow computer is tested as a package including the calculator and its associated measuring instruments and functions. The testing procedures are given in Annex A. DIN E
47、N 12405-3:2016-04EN 12405-3:2015 (E) 8 1 Scope Part 3 of this European Standard specifies the requirements and tests for the construction, performance, safety and conformity of flow computers (FCs) used to meet the metrological and technical requirements of a high accuracy volume conversion device.
48、They are used to determine volume of fuel gases, including those of the first and second families according to EN 437. For the purpose of this European Standard, only flow computers that are intended to operate with ultrasonic meters according to ISO 17089-1 or gas turbine meters conforming to EN 12
49、261 are considered. For the purpose of this European Standard only classification classes E2 and M1 are considered for the flow computer calculator. FCs are equipped with external separate transducers for pressure and temperature which may be approved separately. The provisions concerning pressure and temperature transducers are given in Annex B and C. Requirements and tests are given for energy calculator in EN 12405-2. 2 Normative references The follo
