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Environmental Science/Unit of measurement for SOx and NOx


B. Chorpening wrote at 2010-03-09 22:22:40
The unit /Nm3 is an abbreviated way of saying "per cubic meter at standard temperature and pressure."

N in this case means "normal."

It seems a terrible way to customize a metric unit, due to the confusion it causes.  Its use seems limited to environmental emissions specifications.  

Konrad Miller wrote at 2010-10-21 14:32:34
I have had occasion to work with Mass flow controllers that were purchased from Europe. The unit of flow rate was Nm3/Hr. After some investigation, I found the The "N" stood for "Normal" which is similar to the use of "S" in (for example) SCFM. The "N" spells out a set of conditions (temperature and pressure) which in essence converts the volumetric engineering unit to a Mass engineering unit.

S JAGANNATH wrote at 2016-08-29 12:52:45
I think it is not nano cubic metres  but it is Normal cubic metres  which is referred by NTP OR STP of the gas. Here Mr. Gibson wrongly replied that it is nano cubic metres. Please correct the answer to Mr. Saravana Raja.

S. JAGANNATH from India

Environmental Science

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A R Gibson


The effects of air pollution on LOCAL communities. I have a good grasp on what will effect human health in the air pollution sphere and how to gain improvements. I can also with general air pollution related queries and certain specific problems, for example those air pollution problems caused by TRANSPORT related sources. My main interest is related to AVIATION on which I can also advise on NOISE related matters. I am based in the United Kingdom so most of my knowledge is related to the UK situation.


Seven / eight years dealing with air pollution and noise related matters at the Terminal 5 public inquiry at Heathrow. Now trying to defend my area against a third funway or runway to you.

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