BS EN 17526 discusses gas meters. A gas meter is a specialized flow meter, used to measure the volume of fuel gases such as natural gas and liquefied petroleum gas. BS EN 17526 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 a 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.
These meters have a maximum working pressure not exceeding 0,5 bar and a maximum flow rate 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. BS EN 17526 applies to meters indicating volume at base conditions, which are installed in locations with vibration and shocks of low significance. BS EN 17526 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 and with non-condensing humidity
BS EN 17526 on the specifications on Thermal-Mass Flow sensor gas meters is useful for:
Gas meters are used in residential, commercial, and industrial buildings that consume fuel gas supplied by a gas utility. If no specific requirements are given, the test equipment is traceable to a national or international reference standard error and the uncertainty is equal to or better than for type evaluation: 1/5 of the maximum permissible error (MPE) and for verifications: 1/3 of the maximum permissible error (MPE). When the meter has one or more fast sampling modes in addition to the normal operating mode, then provided the requirements in BS EN 17526 are met, all subsequent tests requiring steady flow profiles in BS EN 17526 are carried out using the same test mode. If the requirements in BS EN 17526 are not satisfied, then all subsequent tests are performed in normal operating mode.
Where specific modes of measurement for managing flow outside the controlled range are present in the normal operating mode, these can be disabled in test mode, unless otherwise specified in BS EN 17526. Provision is made to ensure that any test gas is properly detected by the meter under test. In particular, where the meter has a gas detection system that occurs at a fixed time interval, the gas detection procedure is also performed whenever the test mode is activated. Where the meter provides instantaneous flow rate readings, these can be used as an alternative to volume for calculating the error of measurement at steady flow profiles, unless otherwise specified in BS EN 17526. Using BS EN 17526 you can specify requirements and tests for the construction, performance, safety, and production of battery-powered class 1,5 Capillary Thermal-Mass Flow sensor gas meters.
EN 17526:2021