DIY Gas Analyzer

[victorzamora]

I know there are some kits out there, but are there any good DIY guides/ideas for a gas analyzer? I'm going on a trip in late September and want a CO and O2 analyzer by then. I'm hoping to have a single box with a single intake (probably BC flow limiter like OxyCheq) that will read CO, O2 and hopefully allow for He expansion whenever that's necessary.

 

[fjpatrum]

victor, there's a thread here in DIY for a CO analyzer. Looks pretty simple, relatively cheap, and clean, but it won't do multiple gasses. I haven't seen anyone reference multi-gas sensors that will do what you're looking for all in a single unit. You may be able to buy sensor chips and integrate them on a board yourself. That wouldn't be crazy difficult, if you have any electronics background.

Here's the thread I referenced: http://www.scubaboard.com/forums/co...relatively-inexpensive-co-detector-setup.html

 

[victorzamora]

Sorry for the late response, I've been looking through many threads and trying to find all of the research I could. I have some electronics background, and was thinking it would be fun to buy two (or three) sensors and wire them up using an Arduino. Unfortunately, I couldn't find a CO sensor (best I could find would only read >5ppm) good enough for my wants. I bought an Oxycheq Expedition O2 analyzer and will buy the Sensorcon CO analyzer that you linked to. I saw that thread a few weeks ago and figured instead of $140 on the Sensorcon and >$250 on the Oxycheq ($400 total).....I'd bet I could build an all-in-one for much less than that.

So, for now, this will go on the back burner. However, I will be looking at getting analog readings from the R17 sensor in the Oxycheq analyzer and will look for high quality CO sensor....so that I can create an all-in-one system in the future. However, it seems like He is a totally different sensor. Since it doesn't react with anything, it seems like people are using pretty complicated methods of analyzing He content (more complicated than I'm capable of duplicating).

 

[fjpatrum]

I was thinking along the same lines. I even talked with some of the home CO monitor manufacturers to see what their sensors worked at but it's well outside the range I'd want to use for diving gas analysis. Most of the sensors I found were pre-made units rather than just the chips.