Gas Cylinders - Partial Pressure fill

bbowling@earthlink.net · science forum beginner Joined: 07 Oct 2005 Posts: 2

I am testing a few Nernst O2 sensors and I need to run a pre-determined
gas mixture over the sensors to measure response. I am in the process
of ordering a couple of gas cylinders with a mix of 1% O2 (remainder
N2) and one at 10% O2 (remainder N2). I need these percents as partial
pressures.

The specialty gas company I deal with indicates that they fill cylinder
mixes by weight. I am not an expert in gas cylinder science, so if they
indicate that they fill by weight then do I assume that this is not the
same as a partial pressure mix of the same proportion?

Also, for simple gas mixtures, is there a good source for this, or
should I stick with a specialty gas house?

Thanks in advance for the info - Bruce

Richard · science forum beginner Joined: 10 May 2005 Posts: 24

bbowling@earthlink.net wrote:

bbowling@earthlink.net · science forum beginner Joined: 07 Oct 2005 Posts: 2

To make this clear what I am after is a 1% partial pressure at
atmosphere, which is indeed 76 mm Hg, with the remainder N2.

So, since my gas supplier is mixing with weights, I assume I need to
convert PP at atmosphere for the O2 to mass of O2 at the fill pressure
for the cylinder volume.

I will investigate specifying parts per million with this particular
gas supplier, this would be easier.

- Bruce

Google