DS/EN 17526:2021+A1:2025

Gas meter - Thermal-mass flow-meter based gas meter

This document specifies requirements and tests for the construction, performance, safety and production of battery powered class 1,5 Capillary Thermal-Mass Flow sensor gas meters (hereinafter referred to as meter(s)). This applies to meters having co-axial single pipe, or two pipe connections, which are used to measure volumes of fuel gases of the 2nd and/or 3rd family, as given in EN 437:2018.*In general, the term thermal mass flow meters” applies to a flow-measuring device using heat transfer to measure and indicate gas flowrate, as defined in ISO 14511.*NOTE 1 – Although the word mass” is present in the definition of the measurement principle, gas meters covered by this document provide measurement of gas at base conditions of temperature and pressure.*These meters have a maximum working pressure not exceeding 0,5 bar and a maximum flowrate not exceeding 160 m3/h over a minimum ambient temperature range of 10 °C to +40 °C and a gas temperature range as specified by the manufacturer with a minimum range of 40 °C.*This document applies to meters indicating volume at base conditions, which are installed in locations with vibration and shocks of low significance. It applies to meters in:*– closed locations (indoor or outdoor with protection, as specified by the manufacturer) with condensing humidity or with non-condensing humidity;*or, if specified by the manufacturer:*– open locations (outdoor without any covering) both with condensing humidity or with non-condensing humidity;*and in locations with electromagnetic disturbances likely to be found in residential, commercial and light industrial use.*For meters which indicate unconverted volume, reference can be made to Annex C.*Unless otherwise stated, all pressures given in this document are gauge pressures.*Requirements for electronic indexes, valves and additional requirements for batteries incorporated in the meter and any other additional functionalities are given in EN 16314:2013.*Unless otherwise stated in a particular test, the tests are carried out on meters that include additional functionality devices intended by the manufacturer.*Clauses 1 to 13 are for design and type testing only.