Ultrasonic domestic gas meters

To revise the Annex ZA, and the associated body text only, of EN 14236 to ensure the alignment with the Directive 2014/32/EU.

Ultraschall-Haushaltsgaszähler

Diese Europäische Norm beschreibt die Anforderungen und Prüfungen hinsichtlich der Konstruktion, Funktion und Sicherheit von Klasse 1,0 und Klasse 1,5 batteriebetriebenen Ultraschallgaszählern (im Folgenden Zähler genannt), die einen gleichachsigen Einstutzen- oder Zweistutzenanschluss aufweisen und zur Volumenmessung von verteilten Brenngasen der zweiten und/oder dritten Gasfamilie, wie in EN 437 angegeben, bei maximalen Betriebsdrücken bis zu 0,5 bar ) und maximalen tatsächlichen Durchflüssen bis zu 10 m3/h bei einem Mindestumgebungstemperaturbereich von −10 °C bis +40 °C und einer Mindestgastemperaturspanne von 40 K für Haushaltsanwendungen eingesetzt werden. Diese Europäische Norm gilt für Zähler, bei denen das Messelement und das/die Zählwerke im selben Gehäuse untergebracht sind.
Diese Europäische Norm gilt für Zähler mit und ohne eingebaute Temperaturumwertung, die an Aufstellungsorten, die in geringem Ausmaß Schwingungen und Erschütterungen ausgesetzt sind, und
-   an geschlossenen Aufstellungsorten (in Gebäuden oder im Freien mit vom Hersteller vorgeschriebenem Schutz) mit Betauung oder mit betauungsfreier Feuchte
oder, falls vom Hersteller angegeben,
-   an offenen Aufstellungsorten (im Freien ohne Abdeckung) mit Betauung oder mit betauungsfreier Feuchte
und an Aufstellungsorten mit elektromagnetischen Störungen aufgestellt sind.
Soweit nicht anders angegeben, handelt es sich bei allen in dieser Europäischen Norm verwendeten Drücken um Überdrücke.
Wenn mehr als ein Zählertyp zur Prüfung eingereicht wird, ist es notwendig, jeden Zählertyp gegen diese Europäische Norm zu prüfen.
Die Abschnitte 1 bis 15 und Anhang C gelten nur für Bauart und Typprüfung.
ANMERKUNG   Siehe Anhang A für Produktionsanforderungen.

Compteurs à gaz domestiques à ultrasons

La présente Norme européenne spécifie les exigences et essais de construction, de fonctionnement et de sécurité des compteurs de gaz à ultrasons alimentés par pile de classes 1,0 et 1,5 (ci-après appelés compteurs), ayant des connexions coaxiales à un seul tuyau ou à deux tuyaux, utilisés pour mesurer les volumes de combustibles gazeux distribués de la deuxième et/ou troisième familles, tels qu'indiquées dans l’EN 437, à des pressions maximales de service pouvant atteindre 0,5 bar ) et à des débits réels maximaux pouvant atteindre 10 m3/h sur une plage minimale de température ambiante de  10 °C à +40 °C et une plage minimale de température de gaz de 40 K, pour des applications domestiques. La présente Norme européenne s'applique à des compteurs dont l'élément de mesure et le ou les enregistreurs sont enfermés dans le même boîtier.
La présente Norme européenne s’applique aux compteurs avec ou sans dispositif intégré de compensation de température installés dans des endroits où les vibrations et les chocs sont peu importants et :
-   dans des endroits fermés (à l’intérieur ou à l’extérieur avec la protection spécifiée par le fabricant) avec ou sans condensation d’humidité ;
ou, si le fabricant le spécifie ;
-   dans des endroits ouverts (à l’extérieur sans protection) avec ou sans condensation d’humidité ;
ainsi que dans des endroits avec interférences électromagnétiques.
Sauf indication contraire, toutes les pressions fournies dans la présente Norme européenne sont des pressions relatives.
Lorsque plusieurs types de compteur sont soumis à essai, chaque type de compteur doit être soumis aux essais spécifiés dans la présente Norme européenne.
Les Articles 1 à 15 et l'Annexe C sont fournis uniquement pour la conception et les essais de type.
NOTE   Se reporter à l'Annexe A pour les exigences liées à la production.

Ultrazvočni plinomeri za gospodinjstva

Samo za revizijo dodatka ZA in povezanega telesa besedila standarda EN 14236, da se zagotovi usklajenost z direktivo 2014/32/EU.

General Information

Status
Published
Public Enquiry End Date
31-Aug-2017
Publication Date
06-Nov-2018
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
23-Apr-2018
Due Date
28-Jun-2018
Completion Date
07-Nov-2018

RELATIONS

Buy Standard

Standard
SIST EN 14236:2018
English language
79 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Ultraschall-HaushaltsgaszählerCompteurs à gaz domestiques à ultrasonsUltrasonic domestic gas meters91.140.40Sistemi za oskrbo s plinomGas supply systemsICS:Ta slovenski standard je istoveten z:EN 14236:2018SIST EN 14236:2018en,fr,de01-december-2018SIST EN 14236:2018SLOVENSKI

STANDARDSIST EN 14236:20071DGRPHãþD
SIST EN 14236:2018
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14236
October
t r s z ICS
{ sä s v rä v r Supersedes EN
s v t u xã t r r yEnglish Version
Ultrasonic domestic gas meters Compteurs de gaz domestiques à ultrasons
UltraschallæHaushaltsgaszähler This European Standard was approved by CEN on
t r November
t r s yä

egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä

translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä

CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä

EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre:
Rue de la Science 23,
B-1040 Brussels

t r s z CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN

s v t u xã t r s z ESIST EN 14236:2018

EN 14236:2018 (E) 2 Contents Page European foreword .............................................................................................................................. 5 1 Scope ........................................................................................................................................... 6 2 Normative references ........................................................................................................... 6 3 Terms, definitions and symbols ........................................................................................ 8 3.1 Terms and definitions .......................................................................................................... 8 3.2 Symbols .................................................................................................................................... 11 4 Normal operating conditions ........................................................................................... 13 4.1 Flow range .............................................................................................................................. 13 4.2 Maximum working pressure ............................................................................................ 13 4.3 Temperature range ............................................................................................................. 13 4.4 Range of gases ....................................................................................................................... 14 4.5 Orientation ............................................................................................................................. 14 5 Metrological performance ................................................................................................ 14 5.1 General ..................................................................................................................................... 14 5.2 Mode comparison ................................................................................................................. 15 5.3 Permissible errors ............................................................................................................... 15 5.4 Gas — air relationship ........................................................................................................ 16 5.5 Pressure absorption ............................................................................................................ 17 5.6 Metrological stability .......................................................................................................... 18 5.7 Immunity to contaminants in gas stream .................................................................... 18 5.8 Installation effects ............................................................................................................... 20 5.9 Zero flow .................................................................................................................................. 20 5.10 Reverse flow ........................................................................................................................... 20 5.11 Low flow registration .......................................................................................................... 21 5.12 High flow registration ......................................................................................................... 21 5.13 Pulsed (unsteady) flow ...................................................................................................... 21 5.14 Temperature sensitivity .................................................................................................... 22 6 Construction and materials .............................................................................................. 23 6.1 General ..................................................................................................................................... 23 6.2 Robustness of meter case .................................................................................................. 23 6.3 Corrosion protection ........................................................................................................... 32 6.4 Casework decorative finish .............................................................................................. 38 6.5 Ageing of non-metallic casework ................................................................................... 38 6.6 Ageing of external surfaces of the meter, including index windows and adhesion of the index window ......................................................................................... 39 6.7 Protection against solar radiation ................................................................................. 39 6.8 Resistance to external humidity ..................................................................................... 40 6.9 Flame retardance of external surfaces ......................................................................... 41 6.10 Resistance to storage temperature range ................................................................... 41 6.11 Resistance to the effects of toluene/iso-octane vapour ......................................... 41 6.12 Resistance to water vapour .............................................................................................. 44 6.13 Ageing ....................................................................................................................................... 45 7 Optional features .................................................................................................................. 46 SIST EN 14236:2018

EN 14236:2018 (E) 3 7.1 Pressure measuring point ................................................................................................. 46 7.2 Resistance to high ambient temperature .................................................................... 46 7.3 Meters with temperature conversion ........................................................................... 48 7.4 Ancillary devices (if fitted) ............................................................................................... 48 7.5 Use in hazardous zones ...................................................................................................... 49 8 Index ......................................................................................................................................... 49 8.1 Recording and storage........................................................................................................ 49 8.2 Display ...................................................................................................................................... 49 8.3 Segmental display ................................................................................................................ 49 8.4 Non-volatile memory .......................................................................................................... 50 8.5 Display reset .......................................................................................................................... 51 9 Marking .................................................................................................................................... 51 9.1 All meters ................................................................................................................................ 51 9.2 Two-pipe meters .................................................................................................................. 52 9.3 Durability and legibility of marking .............................................................................. 52 9.4 Accompanying information .............................................................................................. 53 10 Software ................................................................................................................................... 54 10.1 Requirements ........................................................................................................................ 54 10.2 Test ............................................................................................................................................ 54 11 Communications ................................................................................................................... 54 11.1 General ..................................................................................................................................... 54 11.2 Character transmission ...................................................................................................... 54 11.3 Communications protocol ................................................................................................. 55 11.4 Data ........................................................................................................................................... 55 11.5 Test-mode ............................................................................................................................... 56 11.6 Data optical port ................................................................................................................... 58 11.7 Galvanic port (optional) .................................................................................................... 58 11.8 Diagnostics ............................................................................................................................. 58 12 Battery ...................................................................................................................................... 59 12.1 General ..................................................................................................................................... 59 12.2 Voltage interruptions ......................................................................................................... 59 12.3 Minimum operating voltage ............................................................................................. 60 12.4 Battery life .............................................................................................................................. 60 13 Immunity to electromagnetic disturbances ............................................................... 60 13.1 General ..................................................................................................................................... 60 13.2 Electrostatic discharge ....................................................................................................... 60 13.3 Radio frequency electromagnetic field ........................................................................ 61 13.4 Electromagnetic induction (power frequency) ......................................................... 61 13.5 Electromagnetic induction (pulsed field) .................................................................... 62 13.6 Radio interference suppression ..................................................................................... 62 14 Ultrasonic (acoustic) noise interference ..................................................................... 62 14.1 Requirements ........................................................................................................................ 62 14.2 Test ............................................................................................................................................ 63 15 Meters supplied for testing ............................................................................................... 63 Annex A (informative)

Test gases ................................................................................................... 66 A.1 General ..................................................................................................................................... 66 A.2 Test gas properties .............................................................................................................. 66 SIST EN 14236:2018

EN 14236:2018 (E) 4 Annex B (normative)

Production requirements for gas meters ........................................ 67 B.1 Specification ........................................................................................................................... 67 B.2 Technical requirements ..................................................................................................... 67 B.3 Certificates of conformity .................................................................................................. 67 Annex C (normative)

Meters with gas temperature conversion devices ........................ 69 C.1 Scope ......................................................................................................................................... 69 C.2 Metrological performance ................................................................................................ 69 Annex ZA (informative)

Relationship between this European Standard and the Essential Requirements of EU Directive 2014/32/EU Measuring Instruments Directive aimed to be covered ......................................................................................... 73 Bibliography ......................................................................................................................................... 79

SIST EN 14236:2018

EN 14236:2018 (E) 5 European foreword This document (EN 14236:2018) 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, at the latest by April 2019 and conflicting national standards shall be withdrawn at the latest by April 2019. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14236:2007. Changes from previous editions include: — conformity with the MID 2014/32/EU regarding declared errors of the same sign. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive 2014/32/EU. For relationship with EU Directive2014/32/EU, see informative Annex ZA, which is an integral part of this document. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following 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, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 14236:2018

EN 14236:2018 (E) 6 1 Scope This European Standard specifies requirements and tests for the construction, performance and safety of class 1,0 and class 1,5 battery powered ultrasonic gas meters (hereinafter referred to as meters), having co-axial single pipe, or two pipe connections, used to measure volumes of distributed fuel gases of the second and/or third family, as given in EN 437, at maximum working pressures not exceeding 0,5 bar1) and maximum actual flow rates of up to 10 m3/h over a minimum ambient temperature range of -10 °C to +40 °C, and minimum gas temperature span of 40 K, for domestic applications. This European Standard applies to meters where the measuring element and the register(s) are enclosed in the same case. This European Standard applies to meters with and without built-in temperature conversion, that are installed in locations with vibration and shocks of low significance and in — closed locations (indoor or outdoor with protection as specified by the manufacturer) with condensing or with non-condensing humidity or, if specified by the manufacturer, — open locations (outdoor without any covering) with condensing humidity or with non-condensing humidity and in locations with electromagnetic disturbances. Unless otherwise stated, all pressures given in this European Standard are gauge pressures. When more than one meter type is submitted for testing, then each meter type is required to be tested against this European Standard. Clauses 1 to 15 and Annex C are for design and type testing only. NOTE See Annex A for production requirements. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 55032, Electromagnetic compatibility of multimedia equipment - Emission Requirements (CISPR 32) EN 60068-2-5, Environmental testing - Part 2: Tests - Test Sa: Simulated solar radiation at ground level (IEC 60068-2-5) EN 60068-2-30, Environmental testing - Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle) (IEC 60068-2-30) EN 60079-0, Explosive atmospheres - Part 0: Equipment - General requirements (IEC 60079-0) EN 60079-10, (all parts), Explosive atmospheres - Part 10: Classification of areas (IEC 60079-10, all parts)

1) 1 bar = 1 000 mbar = 105 Pa. SIST EN 14236:2018

EN 14236:2018 (E) 7 EN 60079-11, Explosive atmospheres - Part 11: Equipment protection by intrinsic safety “i” (IEC 60079-11) EN 60079-15, Explosive atmospheres - Part 15: Equipment protection by type of protection "n" (IEC 60079-15) EN 60086-1, Primary batteries - Part 1: General (IEC 60086-1) EN 60086-4, Primary batteries - Part 4: Safety of lithium batteries (IEC 60086-4) EN 60529, Degrees of protection provided by enclosures (IP Code) (IEC 60529) EN 60695-11-5, Fire hazard testing - Part 11-5: Test flames - Needle-flame test method - Apparatus, confirmatory test arrangement and guidance (IEC 60695-11-5) EN 60695-11-10, Fire hazard testing - Part 11-10: Test flames - 50 W horizontal and vertical flame test methods (IEC 60695-11-10) EN 60730-1:2000, Automatic electrical controls for household and similar use - Part 1: General requirements (IEC 60730-1:1999) EN 61000-4-2, Electromagnetic compatibility (EMC) - Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test (IEC 61000-4-2) EN 61000-4-3, Electromagnetic compatibility (EMC) - Part 4-3: Testing and measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test (IEC 61000-4-3) EN 61000-4-8, Electromagnetic compatibility (EMC) - Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test (IEC 61000-4-8) EN 61000-4-9, Electromagnetic compatibility (EMC) - Part 4-9: Testing and measurement techniques — Impulse magnetic field immunity test (IEC 61000-4-9) EN 61000-6-1, Electromagnetic compatibility (EMC) - Part 6-1: Generic standards - Immunity for residential, commercial and light-industrial environments (IEC 61000-6-1) EN 61000-6-2, Electromagnetic compatibility (EMC) - Part 6-2: Generic standards - Immunity for industrial environments (IEC 61000-6-2) EN 62056-21:2002, Electricity metering - Data exchange for meter reading, tariff and load control - Part 21: Direct local data exchange (IEC 62056-21:2002) EN ISO 1518 (all parts), Paints and varnishes - Determination of scratch resistance (ISO 1518) EN ISO 2409, Paints and varnishes - Cross-cut test (ISO 2409) EN ISO 2812-1:2017, Paints and varnishes - Determination of resistance to liquids - Part 1: Immersion in liquids other than water (ISO 2812-1:2017) EN ISO 4628-2:2016, Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 2: Assessment of degree of blistering (ISO 4628-2:2016) SIST EN 14236:2018

EN 14236:2018 (E) 8 EN ISO 4628-3:2016, Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 3: Assessment of degree of rusting (ISO 4628-3:2016) EN ISO 4892-3, Plastics - Methods of exposure to laboratory light sources - Part 3: Fluorescent UV lamps (ISO 4892-3) EN ISO 6270-1, Paints and varnishes - Determination of resistance to humidity - Part 1: Condensation (single-sided exposure) (ISO 6270-1) EN ISO 6272-1, Paints and varnishes - Rapid-deformation (impact resistance) tests - Part 1: Falling-weight test, large-area indenter (ISO 6272-1) EN ISO 9227, Corrosion tests in artificial atmospheres - Salt spray tests (ISO 9227) ISO 834-1, Fire-resistance tests - Elements of building construction - Part 1: General requirements ISO 7724-3, Paints and varnishes - Colorimetry - Part 3: Calculation of colour differences ASTM D471, Standard Test Method for Rubber Property - Effect of Liquids ASTM D1003, Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics 3 Terms, definitions and symbols 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 actual flow rate flow rate at the gas pressure and gas temperature conditions prevailing in the gas distribution line in which the meter is fitted, at the meter inlet 3.1.2 base conditions fixed conditions to which a volume of gas is converted (i.e. base gas temperature 15 °C, base gas pressure 1 013,25 mbar) 3.1.3 contaminants gas borne dust, vapour and other substances that could affect the operation of the meter 3.1.4 communications port galvanic or optical serial data port 3.1.5 display device (e.g. liquid crystal display) which shows the contents of a memory (e.g. registered volume or flags) SIST EN 14236:2018

EN 14236:2018 (E) 9 3.1.6 distributed gas gas locally available 3.1.7 error of indication (Ð) value which shows the relationship in percentage terms of the difference between the volume indicated by the meter and the volume which has actually flowed through the meter, to the latter volume: ∈=ic c-×100VVV where Vi

is the indicated volume in cubic metres (m3); Vc

is the volume in cubic metres (m3) that has actually flowed through the meter 3.1.8 external leak tightness leak tightness of the gas carrying components of the gas meter with respect to the atmosphere 3.1.9 flag single alphabetic character on the index giving a visual signal of significant events and/or change(s) in the operation of the meter 3.1.10 galvanic connection/interface hard wired serial connection or pulse output from the meter 3.1.11 index all that which is viewed through the index window, including the display 3.1.12 index window(s) area(s) of transparent material through which the index can be read 3.1.13 maximum error shift maximum mean error shift at any of the tested flow rates 3.1.14 maximum working pressure upper limit of the working pressure for which the meter has been designed, as declared by the manufacturer and marked on the index or the data plate 3.1.15 mean error arithmetic mean of consecutive errors of indication at a flow rate SIST EN 14236:2018

EN 14236:2018 (E) 10 3.1.16 measuring element part of the meter which produces an electrical signal proportional to the gas flow rate 3.1.17 memory element which stores digital information 3.1.18 meter case complete meter, not casing only 3.1.19 meter class class to which a meter belongs, according to the metrological requirements of this European Standard, i.e. class 1,5 or class 1,0. 3.1.20 meter cover rigid enclosure on the front of the meter made either wholly of transparent material, or of opaque material provided with index window(s) 3.1.21 normal conditions of operation conditions referring to the meter operating: — at a pressure up to the maximum working pressure (with or without a flow of gas); — within the range of flow rates; — within the ambient temperature range; — within the gas temperature range; — with the distributed gas 3.1.22 operating mode method (sample frequency and timing) of obtaining volume flow measurements 3.1.23 optical port serial data port using an infra-red transmitter and receiver 3.1.24 pressure absorption difference between the pressure measured at the inlet and outlet connections of the meter whilst the meter is operating 3.1.25 pressure measuring point permanent fitting on the meter outlet enabling a direct measurement of the outlet pressure to be obtained SIST EN 14236:2018

EN 14236:2018 (E) 11 3.1.26 range of mean errors difference between the minimum and maximum mean errors over a specified flow range 3.1.27 regression line straight line, generated using a statistical method, to give a graphical representation of a set of results 3.1.28 register electronic device comprising both memory and display, which stores and displays information 3.1.29 segment individual part of a display which is able to show a portion of a character 3.1.30 starting flow rate lowest flow rate at which the meter is able to indicate a volume of gas passed 3.1.31 temperature conversion device device which converts the measured volume to a corresponding volume at base gas temperature 3.1.32 Test House organization used to perform prescribed tests on meters, in accordance with this standard 3.1.33 thermal cut-off valve heat sensitive valve used to cut off the flow of gas to the meter if the ambient temperature rises above a predetermined level for a specified time 3.1.34 ultrasonic gas meter gas meter that uses ultrasound and that is designed to measure, memorise and display the fuel gas volume that has passed through it 3.1.35 ultrasonic transducer device used to generate and detect the ultrasound signals within the meter 3.1.36 working pressure pressure of the gas at the inlet of the meter 3.2 Symbols 3.2.1 D outside diameter of the pipe in millimetres (mm) SIST EN 14236:2018

EN 14236:2018 (E) 12 3.2.2 g -2) 3.2.3 MPE maximum permissible error, in percent (%) 3.2.4 pmax maximum working pressure 3.2.5 Qmax maximum flow rate, specified in cubic metres per hour (m3/h) for which the meter has been designed 3.2.6 Qmin minimum flow rate, specified in cubic metres per hour (m3/h) for which the meter has been designed 3.2.7 Qr overload flow rate, the highest flow rate at which the meter operates for a short period of time without deteriorating 3.2.8 Qstart lowest flow rate at which the meter is capable of registering the passage of gas, as declared by the manufacturer 3.2.9 Qt transitional flow rate, occurring between the maximum and minimum flow rates at which the flow rate range is divided into two zones, the ‘upper zone’ and the ‘lower zone’ NOTE Each zone has a characteristic maximum permissible error. 3.2.10 tb base gas temperature 3.2.11 tb,i base gas temperature for meters declared suitable for differential temperature and intermittent operation 3.2.12 Ti temperature at meter inlet SIST EN 14236:2018

EN 14236:2018 (E) 13 3.2.13 tm ambient temperature of the meter 3.2.14 tg gas temperature range of the meter 3.2.15 tsp specified centre temperature for a temperature converted meter 4 Normal operating conditions 4.1 Flow range The values of maximum flow rates and those corresponding values of the upper limits of the minimum flow rates shall be those given in Table 1. Table 1 — Flow range Qmax Upper limits of Qmin m3/h m3/h 2,5 0,016 4 0,025 6 0,040 10 0,060 The definitions of the meter classifications applicable in this European Standard are given in Table 2. Table 2 — Flow rate ranges by meter classification Class Qmax/Qmin Qmax/Qt Qr/Qmax 1,5

s w r
s r
sá t 1,0
s w r
sá t 4.2 Maximum working pressure The manufacturer s
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.