The USNWG works to promote, encourage, and participate in the establishment of a comprehensive set of legal metrology standards for commercial measurement of hydrogen for vehicle and other refueling applications including (1) device design, accuracy, installation, and use requirements; (2) method of sale requirements; (3) test procedures; and (4) fuel quality standards. The ultimate goal is that these standards will ensure the accuracy of measurements, enhance consumer protection, foster fair competition, and facilitate economic growth and trade.
The USNWG works through in-person meetings, conference calls, and email. The USNWG is currently accomplishing its goals through two subcommittees; one works to simultaneously refine equipment standards and test procedures and a second works on fuel specification requirements. For questions about meeting summaries and agendas please send a request to the USNWG Contact available through the Resources Helpful Hydrogen Links and Contacts listed below.
Upcoming for the 2019 weights and measures standards development process cycle is the California Division of Measurement Standards proposal submitted on NIST Handbook (HB) 44 Section 3.39 Hydrogen Gas-Measuring Devices – Tentative Code for a change from tentative code status to permanent along with several modifications. The only changes made to the code since its 2010 addition to HB 44 as a tentative code were in 2016 to expand the device tolerances from 1.5 % and 2.0 % to 5.0 % and 7.0 %. California is the only state that has with some modification upgraded the code’s status to permanent and is using the code in its enforcement activities. Proposed modifications to HB 44 Section 3.39 are for:
- updating the code to permanent status with a January 1, 2020 enforcement date;
- citing the specific applicable fuel quality standard, i.e., SAE J2719 H2 Fuel Quality for Fuel Cell Vehicles;
- reducing the size of the required larger test draft to the lesser quantity of five times the MMQ rather than ten times the MMQ or a draft at 4 kg instead of 1 kg, whichever is larger;
- limiting the test draft size for repeatability tests to no less than 1000 indicated divisions of the device under test; and
- updating references to density publications and websites as well as an update and move of the definitions into Appendix D.