Thanks for your comments on my response to the original question.
If you will read some of the many previous threads on essentially this same question, you will find some responses stating that Normal conditions are not
always defined as 0 deg C and 1 atmosphere ... and that is why I said "usually but not always".
As for SCF, in the 40+ years that I worked in the U.S. petroleum industry, SCF was defined as being at 60 deg F and 14.696 psia (i.e., 1 atmosphere) rather than 14.5 psia.
Again, reading some of the many previous threads on this question, there are literally more than half a dozen definitions of SCF, Sm3 and Nm3. Just as one example, our U.S. EPA defines standard conditions as 1 atmosphere and 68 deg F (i.e., 20 deg C). As another example, since 1982, the International Union of Pure and Applied Chemistry (IUPAC) has defined standard conditions as being 0 deg C and 100 kPa (which is 1 bar) whereas 1 atmosphere is 101.325 kPa. Finally, the American Gas Association uses both 60 deg F and 14.696 psia as well as 60 deg F and 14.73 psia.
The lesson to be learned is that we should always state what standard conditions are being used.
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