Conversion of ppmv's from real to STP
Conversion of ppmv's from real to STP
(OP)
Hello,
Can anyone please help me? I need to convert the ppmv value that I measure at an extraction point of gas at a given temperature and pressure to Standard Temperature and Pressure. I thougt it was an easy operation but I found myself in quite a trouble. I'll apreciate any help.
thank you
lfbg
Can anyone please help me? I need to convert the ppmv value that I measure at an extraction point of gas at a given temperature and pressure to Standard Temperature and Pressure. I thougt it was an easy operation but I found myself in quite a trouble. I'll apreciate any help.
thank you
lfbg





RE: Conversion of ppmv's from real to STP
I presume the contaminant is not a solid because then you would not be expressing it as ppm - rather as mass per volume.
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: Conversion of ppmv's from real to STP
Where you may have a problem (other than those pointed out in Katmar's excellent response) is in determining what Standard Temperature and Pressure to use ... unless it is spelled out in some pertinent document involved in your work. See http://
Milton Beychok
(Visit me at www.air-dispersion.com)
.
RE: Conversion of ppmv's from real to STP
In fact, I am dealing with biogas. I am extracting about 5000 Nm3/h and my contaminant is hydrogen sulfide (H2S). I get a value of around 1300ppm (I am assuming that it is in volumetric terms because my company assumes so).
So if I understand well, this value can be considered as already at STP, even if the measuring devices do not do this conversion?
Thanks again
lfbg
RE: Conversion of ppmv's from real to STP
As Katmar has clearly explained, yes. Another designation sometimes used instead of ppmv is μmol/mol.