DIY gas sensors?

[CuNanoTube]

Bagging each sample may not be a terrible plan. If one used a balloon or condom as a chamber you could fill it with the sample and use the diameter as a pressure indicator.

 

[gsk3]

Bagging each sample may not be a terrible plan. If one used a balloon or condom as a chamber you could fill it with the sample and use the diameter as a pressure indicator.

My concern is that I might not check every tank if it adds a several minute step. Goal is one hookup to inflator hose to flow the gas past the O2, CO, and He sensors.

 

[lucca brassi]

May I ask whay is CO (carbon monoxide ) nedded ?

 

[CuNanoTube]

CO is very dangerous in breathing gas as when you dive deep the partial pressure of the CO increases. A low level at 1 ATA may not be dangerous, but a 5 it is a huge concern.

 

[CuNanoTube]

On topic, we may need to do some testing to figure out what the best method is. I would offer my services except I am on an academic term until may and do not have access to a lab. (which is too bad really, I'll see if I can work something out, I know we have a bottle of CO, a LP regulator and some very precise flow meters.)

 

[gsk3]

On topic, we may need to do some testing to figure out what the best method is. I would offer my services except I am on an academic term until may and do not have access to a lab. (which is too bad really, I'll see if I can work something out, I know we have a bottle of CO, a LP regulator and some very precise flow meters.)[/QUOTE

Cool. If we can get this working, it would be a real service to the community. These things should not cost $300....

 

[Lobzilla]

Are we now focusing on CO detection?

If yes, I would like to try how the inexpensive (>20ppm) CO sensors perform at the intermediate pressure of our regulator sets. The idea is to hook the test chamber with detector up to the BC inflator hose, let the gas flow through the chamber and exit via a needle valve, close the valve, and test the gas at ~10bar.

 

[gsk3]

Are we now focusing on CO detection?

If yes, I would like to try how the inexpensive (>20ppm) CO sensors perform at the intermediate pressure of our regulator sets. The idea is to hook the test chamber with detector up to the BC inflator hose, let the gas flow through the chamber and exit via a needle valve, close the valve, and test the gas at ~10bar.

I agree this is the top priority. Shouldn't be too hard to make a chamber for the sensor out of PVC, and that will keep the volume down to something quite manageable.

Needle valve almost certainly not necessary. Orfice + cheap ball valve will be much cheaper.