EN 12261:2018

European foreword
1 Scope
2 Normative references
3 Terms, definitions and symbols
4 Meter classification
5 Metrological performance requirements
6 Design and material requirements
7 Meter output
8 Marking
9 Documentation
Annex A (normative) - Test facility specifications
Annex B (normative) - Perturbation testing
Annex C (informative) - Recommendations for use
Annex D (normative) - Individual factory testing
Annex E (normative) - Metrological requirements
        and tests for each meter prior to dispatch
        (Individual meter testing)
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
Bibliography

This document specifies the measuring conditions, requirements and tests for the construction, performance and safety of class 1,0 axial and radial turbine gas meters with mechanical indicating devices, herein after referred to as a meter(s), having in-line pipe connections for gas flow measurement.This document applies to turbine gas meters used to measure the volume of fuel gases of the 1st and 2nd gas families, the composition of which is specified in EN 437, at maximum working pressures up to 420 bar, actual flow rates up to 25 000 m³/h over a gas temperature range of at least 40 K and for a climatic environmental temperature range of at least 50 K.This document applies to meters 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 humidityor, if specified by the manufacturer,-open locations (outdoor without any covering) with condensing humidity or with non-condensing humidityand in locations with electromagnetic disturbances.Unless otherwise specified in this document:-all pressures used are gauge;-all influence quantities, except the one under test, are kept relatively constant at their reference value.