[USMA:41311] U.S. National Work Group specifies the kilogram for hydrogen fuel sales

[Paul Trusten]

U.S. industry, not just California, wants the kilogram as the unit of 
measurement for hydrogen fuel sales. Also, another SI unit could make 
its debut before the U.S. public: the megapascal. But, the bar is 
another possibility being debated for a hydrogen delivery pressure unit.

NIST has formed a U.S. National Work Group for the Development of 
Commercial Hydrogen Measurement Standards (USNWG). At its 19 June 2008 
meeting, the USNWG proposed that retail hydrogen dispensing devices 
dispense hydrogen fuel only by the kilogram, and also the delivery or 
service pressure of the dispenser in either bars or megapascals (the 
meeting attendees did not settle on the unit of pressure, but offered 
those two possibilities).

NIST Weights and Measures Division is developing a hydrogen fuel Web 
site to enable the public to follow these issues as they develop.  
NIST's Laws and
Metric Group will let us know when the site is launched.

Personally, I have noticed that some hydrogen dispensers have their 
service pressures dual-labeled in SI and customary units (bar and pounds 
per square inch [see attachment and also 
http://www.hydrogencarsnow.com/hydrogen-filling-station-irvine-ca.htm]). 
Perhaps the USNWG can be persuaded in its deliberations to adhere to SI 
as the preferred system of measurement for U.S. trade in hydrogen (as it 
is legally for all U.S. trade according to the Metric Conversion Act), 
and specify hydrogen mass delivery in kilograms only and pressure 
delivery in megapascals only.

--
Paul Trusten, R.Ph.
Public Relations Director
U.S. Metric Association (USMA), Inc.
www.metric.org
3609 Caldera Blvd., Apt. 122
Midland TX 79707-2872 US
+1(432)528-7724
mailto:[EMAIL PROTECTED]



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