Quote:
| Originally Posted by johnmaneely I'm thinking of using this in a bodge up rebreather, probably all manual control for fun in shallow water, not a o2 analyzer as the article, presume it makes no difference apart from the decimal point position. |
Well one kills you and the other doesn't but aside from that...
You are normally dealing with a cell that gives about 12mV in air, 60mV in pure O2 at 1 bar and you can factor from there.
You just read a voltage, apply a calibration factor that varies from day to day and read it out as either a percentage or bar.
You are talking about a device that is roughly linear- for the one I use that's 2% fsd a constant temperature and 5% fsd over it's quoted temperature range. To get enough volts on most A2Ds you may find you have to amplify it or your quantisation will show. If you don't amplify beware of the input load requirements on D2As - some want a very low source impedance.
Most home builders use a ready made display but that wouldn't make much of a project. If you're diving it think about oil filling the thing. Watch the display type. It's a lot easier than watertight boxes that always sound easy, sound like you can just buy one but somehow it never works out like that.
Good luck with it.