U.S. National Work Group (USNWG) for the Development of Commercial Hydrogen Measurement Standards Update
Juana Williams, National Institute of Standards and Technology


The USNWG met on December 2-4, 2008 at MicroMotion, Inc. in Boulder, Colorado.  The meeting was sponsored by DOE and NIST.  The USNWG work continues in year two of a five year plan to promote the establishment of a uniform and comprehensive set of legal metrology requirements for equipment used in hydrogen measurements for vehicle and other refueling applications. 

Test procedures
Inspection and test procedures for commercial equipment are based on NIST Handbook 44 (H44) requirements.  The USNWG Device Standards Subcommittee (DSS) is moving forward to establish preliminary minimum specifications for test standards, suitable laboratory and field test procedures, and guidelines.  Work began in November 2008 to conduct preliminary analysis of the uncertainties associated with the gravimetric, volumetric, and master meter test methods permitted for use to verify the performance of commercial hydrogen dispensing equipment.

Device Requirements
As a result of the December 2008 meeting, the DSS will make Draft 3.3 of the NIST Handbook 44 Hydrogen Gas Measuring Devices Code available to the January 2009 National Conference on Weights Measures, Inc. (NCWM).  This will be the first time the draft code appears on a national agenda.

Fuel Quality Specifications
The USNWG Fuel Specification Subcommittee (FSS) recommends that the weights and measures community consider adoption of the hydrogen fuel quality standard that was adopted as an interim standard by the State of California in September 2008 until a national or international standards body recognizes this or another standard.  This FSS proposal will be distributed for the first time for national review by the weights and measures community at the January 2009 NCWM Interim Meeting.  The FSS has proposed one fuel quality standard for both internal combustion engine and fuel cell vehicles. 

Method of Sale Requirements
The FSS addressed 16 CFR Part 309 Federal Trade Commission (FTC) Labeling Requirements for Alternative Fuels and Alternative Fueled Vehicles and will modify its proposal for NIST Handbook 130 (H130) Laws and Regulations and Engine Fuel Quality to recognize this FTC requirement.

Development of International Standards
The Secretariat (the Netherlands) for International Organization of Legal Metrology (OIML) Recommendation 139 (R 139) "Compressed Gaseous Fuel Measuring Systems for Vehicles" has distributed the first working draft (1WD) of the international standard for review and comment.  The 2008 document is the OIML model regulation for equipment used to deliver compressed gases (natural gas, hydrogen, etc.) as a fuel into motor vehicles, small boats, and aircraft.  There are several sections that raise questions that require input from stakeholders.  The most notable of these questions are as follows: (1) Do the requirements that permit national legislation to apply rather than a single uniform international standard create trade barriers? (2) Is software adequately addressed? (3) Should the language set parameters for physical seals and electronic security or be more general? and (4) Should tests at constant flow rates be mandatory and are they achievable in today's laboratories?

NIST WMD will distribute the 1WD for R 139 the week of January 5, 2009 to gather input by March 1, 2009 from U.S. stakeholders so that it can establish a U.S. position on the 1WD. 

To participate in the USNWG for these national (H44 and H130) and/or international (R 139) requirements, please contact Juana Williams (National Institute of Standards and Technology, Weights and Measures Division) by email at juana.williams@nist.gov.