John,
Now you're talking U.S. law and regulation regarding a particular
application: labeling.
It is perfectly fine to specify which form of a unit should be used in
certain applications if one wishes to standardize **practice**. For
example, the ICAO might decide to specify that all flight altitudes
should be given in kilometers. Woe betide the pilot who is assigned to
fly at 1000 dam but hears that as 1000 m. By limiting altitude
information, reporting, and direction to one specific form, the meter, a
large number of potential problems are obviated.
But, NIST is the NMI and WMO for the U.S. Therefore, as a matter of
general practice, they see the meter and the dekameter as being equally
valid **in general**, that is, as far as SI goes. For NIST to state a
universal practice for all applications would be neither practical nor
desired.
Jim
John M. Steele wrote:
I agree with Jim F's comments, but I would like to make an additional point.
NIST was the technical advisor (and possibly ghostwriter) for the FTC's
detailed rules in support of the FPLA, and advisor to NCWM on the
language of the UPLR. As a matter of state and Federal law, the
centimeter is an approved unit of length in that legislation (in the
range 1.00 - 999 cm). So their position seems pretty clear and happens
to be different from yours. (In squared and cubed form, also permitted
for area and volume within applicable ranges).
Current laws would require amendment to say it can't be used for trade.
--- On *Thu, 7/30/09, Robert H. Bushnell /<roberthb...@comcast.net>/* wrote:
From: Robert H. Bushnell <roberthb...@comcast.net>
Subject: [USMA:45460] centimeter
To: "U.S. Metric Association" <usma@colostate.edu>
Cc: usma@colostate.edu
Date: Thursday, July 30, 2009, 1:10 PM
Does NIST have any comments, reports, policies or recommendations
about the use of centimeter? Or not use of centimeter.
I want everyone to stop using centimeter. How are we to convert to
SI if, when we hear centimeter we think, "now how many inches is that"?
Centimeter causes this problem because it is near the size of the inch.
This makes it hard to stop using inches. People keep comparing
centimeters to inches.
Millimeter does not have this problem.
Can NIST help get rid of inches?
Thanks for your ideas.
Robert Bushnell, PhD PE
member USMA
member ASTM
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