OIML R139-1:2018 Compressed gaseous fuel measuring systems for vehicles

This OIML Recommendation consists of three parts: Part 1: Metrological and technical requirements, Part 2: Metrological controls and performance tests, Part 3: Report format for type evaluation.The 2018 edition supersedes the 2007 and 2014 editions, introducing updated provisions for hydrogen refuelling systems, including requirements for pressure ramps, temperature compensation, minimum measured quantity (MMQ), maximum permissible errors (MPE), durability testing, and depressurization corrections.