VOC concentration conversion (PID)

[christelle]

Hello,

I need an information about the conversion of VOC concentration.
I have a real concentration measured with a PID detector. The gas I analyse is a mixture of several alcools. I have calculated the response factor of the mixture and the average weight molar. So, I obtain the real concentration in ppm(vol), that I can convert in mg/Nm3.

But, I have to communicate the results to an organism in total carbon equivalent. I don't know how to convert from real ppm to equivalent carbon ppm.

With the FID technology, I know that there is a factor of 3 to apply from ppm C3H8, to ppm equivalent carbone. Is it the same thing with PID ?
How can I compare FID and PID results...

Sorry for my english level. Thanks for your answers.

Christelle.
FRANCE
tavernic@essilor.fr

 

[ALEXFV]

Good night:

Sorry for delay on response...I'm new in this forum.

So, you can check for PID factors at BWT page (

http://www.gasmonitors.com)

or at RAE wab page...There's some interesting articules regarding PDI and FID.

They aren't the same: Photoionization detector converts a signal that comes from an electric-excited ion, meanwhile flame ionization compares an spectrum from a VOC against hydrogen signal response.

Hope this could help you.