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Specialty Chemistry Forums => Chemical Engineering Forum => Topic started by: aliveinmoscow on December 02, 2010, 04:53:47 AM

Title: Mixing two gases to get desired ppm
Post by: aliveinmoscow on December 02, 2010, 04:53:47 AM

I have to mix 2 gases, Hydrogen and Nitrogen to achieve a constant flow of mixed gas with 100, 200... 1000 ppm of H2 in the mixture.

I have mass flow meters to adjust the flow of each individual gas but how do I determine what they should read to achieve each of the desired ppm combinations

Title: Re: Mixing two gases to get desired ppm
Post by: Stepan on December 04, 2010, 09:07:50 AM

In chemistry of gases, ppm usually stands for "ppm by volume". If this is what you need to achieve, than Hydrogen flow needs to be 100/1,000,000; 200/1,000,000 ; and 1,000/1,000,000 of the Nitrogen flow correspondingly.