the monitors you are talking about would be useles to you as they monitor blood oxogen which is fine but it's far to late to find out your blood o2 is to low and you now need to inject more o2 but you dont have the energy before you pass out! you need to know your o2 before you breather it,
another problem with the medical clip on is that it would need bear skin to shine though to take a reading,this could be a big problem in colder water, and when you are cold you blood will move to your inturnal bit and pieces so there would be no blood to get a reading from.
although sensers are expensive they are the cheepest way to monitoe o2,
they have no drain on your ciruit as they are batterys of a type so all you need is power to drive your voltmeter display
are you thinking of using LED or LCD?
remember that you have to increse the gain on the display and incorperate a refferance voltage for the display for calibrating
it's all very simple as im shoure you know but please be very awere this is for life surport and getting this wrong may very well kill your brother
i've just tested my new displays today inwater at stoney to 30m which went great!
kind regards john routley
Quote:
| Originally Posted by Tansis Hello all,
my younger brother has roped me in for a project to build his own CCR , he's the scuba fan , as for me I'm the electronics boffin of the family.( Personally I think it's part of a fiendish plot to have me freezing my ass off up at stony cove to get qualified so I can be his dive buddy.)
Now I've looked around the web and as far as I can tell every commercial and homebrew rig uses an oxygen sensor that is built into the hardware. From an electronics point of view it's not that difficult to make my own but they are expensive and can be a significant drain on a battery power supply, as this is of critical importance to safe operation I wondered if there was a alternative method that used less power and a cheaper sensor.
Suffice to say I found one. Hospitals use a simple clip on device that attaches to a finger or earlobe that can measure oxygen concentration actually in the blood stream by using nothing more than a couple of light emitting diodes. (This is perhaps a gross over simplification I admit )
My question is , has this approach been considered and rejected for whatever reason or is it an avenue worth exploring? |