scope:

This European Standard specifies functional requirements for the design, construction, testing, commissioning/decommissioning, operation, maintenance and where appropriate calibration, together with suitable documented provisions for all new gas measuring systems and any major changes of existing systems used for custody transfer. This European Standard also specifies accuracy classes of measuring systems and thresholds applicable to these classes. Demonstration of compliance is achieved through the selection, installation and operation of appropriate measurement instruments, together with suitable documented provisions for calculations. Examples of demonstration of compliance are provided for each accuracy class; however, they are not prescriptive solutions. This European Standard is applicable for gases of the 2nd family according to EN 437. It is also applicable for treated non-conventional combustible gases complying with EN 437 and for which a detailed technical evaluation of the functional requirements (such as injected biomethane) is performed ensuring there are no other constituents or properties of the gases that can affect the integrity of the measuring systems. This European Standard can also be used as a guideline for 1st and 3rd family gases according to EN 437; however additional considerations can be necessary. This European Standard is not applicable for raw or sour gases. This European Standard gives guidelines when designing, installing and operating gas meters with additional functionalities (smart meters). Unless otherwise specified all pressures used in this European Standard are gauge pressures. For associated pressure regulating systems the requirements of EN 12186 and/or EN 12279 apply. For requirements on design, housing, lay-out, materials for components, construction, ventilation, venting and overall safety of gas measuring systems within the scope of this European Standard, EN 15001, EN 12186, EN 12279 and/or EN 1775 apply ...