difference between ppm and vpm


Thread Starter


what is difference between volume per millions
and parts per millions in case of gas

is there is any conversion factor between them

Ian Verhappen

In a word Density. Assuming you mean ppm is ppm(w) by weight. This is why it is ALWAYS a good idea to state what basis you are using for your ppm measurement. vpm = ppm(v).

Ian Verhappen
Syncrude Canada Ltd.
PO Bag 4009, MD 0032
Fort McMurray, Alberta T9H 3L1
P 780 790-4079, Cell 799-6017
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Thomas Davis

At Different pressures gases have different densities so the number of mulecules can vary per volume. The conversion would be a simple ratio if you know the number of particles per a given volume at a given pressure and the pressure you are using.