OIML R139 for Hydrogen dispensers
Recently NMi attended the OIML R139 Hydrogen dispensers meeting, held in Japan to kick off the new project. OIML R139 is about Compressed Gaseous Fuel Measuring Systems for Vehicle. This project was started by the Japanese delegation to implement Hydrogen dispensers into the already excisting OIML R139 recommendation. The current recommendation was already usable for CNG dispensers but not for Hydrogen dispensers because of some specific elements. Since there is a big push for these kind of systems in Japan, the meeting was held in Yokohama with a large Japanese delegation.
Accuracy class 5 achievable now
During the two day meeting a lot of “hot” topics were discussed to see if it was possible to already agree on these. A major part of the sessions was spent on the discussion which accuracy class(es) had to be applicable for Hydrogen dispensers. Furthermore the related topics and possible increasement of the accuracy class were discussed. Conclusion: at this moment it is achievable to have an accuracy class 5 (error may be 4% for type evaluation and 5% for installations in use) but developing technology in the next couple of years would make an accuracy class 3 (Error may be 2% for type evaluation and 3% for installations in use) more suitable. This would mean for example that dispenser manufacturers will have to improve the measurement under 700 bar pressure and lower the uncertainty of the amount of gas in the system hose.
By the end of 2017 we hope to have solved all technical discussions
Marc Schmidt attented this meeting for NMi. “We hope to solve all technical discussions by the end of this year which would mean that we can finalize and publish the revised OIML R139 by the end of 2018. To have this document published within 2 years after starting the project would be a milestone in OIML world. We hope -and do our outmost- to achieve this. Together and in cooperation with all participating countries”.