Assumed basis of PPM
Assumed basis of PPM
(OP)
I see "PPM" used as a (dimensionless) unit of gas species concentration quite a lot. I kind of assume it's normally an implied mole (volume) fraction, but don't really know why. Or if others do too. Indeed I can't remember ever seeing it clarified in print, just "PPM".
Any/all anecdotal evidence welcomed.
Any/all anecdotal evidence welcomed.
Steve





RE: Assumed basis of PPM
RE: Assumed basis of PPM
je suis charlie
RE: Assumed basis of PPM
RE: Assumed basis of PPM
True. So frustrating when publications don't feel the need to include vital information like this (mass vs volume ratio).
I did a straw poll around some of my colleagues to see if anyone knew whether the 21% oxygen in typical atmospheric air was by volume or by mass. Most looked a bit uneasy and didn't really know the correct answer.
Steve
RE: Assumed basis of PPM