This European Standard specifies the requirements and tests for the construction, performance and safety of diaphragm gas meters (hereinafter referred to as meters) having co-axial single pipe, or two pipe connections, used to measure volumes of fuel gases of the 1st, 2nd and 3rd families according to EN 437:1993, at maximum working pressures of up to 1 bar and maximum actual flow rates of up to 160 m3/h over a minimum ambient and gas temperature range of -5°C to + 35 °C.