W W Meixner
Banned
Reasonable? Not to me. Co2 monitoring on a dolphin? This is really crazy and I don't think has ever been done. You will need a whole suite of electronics, batteries and pass through ports that have never existed for any drager which is about as minimalist as it can be electricity-wise. You could probably make something up with parts from Martin at tec-me (in Germany) but for the price and complete lack of any functional testing I think you are better off either skipping this modification or looking at a second hand unit CCR (not SCR) that already has Co2 monitoring.
The way the dolphin (and ray) were supposed to work is that your SCR supply gas is also your bailout. The supplied drager regulator is fine for cold water.
RJ...
The OP is talking about PPO2 monitoring...oxygen percentage...not CO...
For Drager units...Drager made a simple PPO2 monitor...''OXYgauge''...hard to find a good one these days...the first generation units had a two piece housing...that was prone to leaking as it aged due to the adhesive used to affix the two housing pieces together crystallizing...allowing water into the unit...salt water intrusion destroys the board...
Martin Tolksdorf...TECME...out of Dusseldorf makes a good one...TFT...with compatible Fischer cable and single cell P-Port sensor house...unit works great and is a direct fit with the Drager SCR rebreathers...
For the Drager Ray...Martin also makes an ''in-loop'' sensor house that gets the sensor out of the water trap at the bottom of the Ray scrubber...this part allows for a much more accurate PPO2 reading on your handset as the in-loop sensor house is ''post'' NITROX injection...just prior to ''inhalation''...
Martin also makes a Ray ''scrubber'' extension'' kit which includes a longer outer housing and an inner center tube extension...
W S Water Safety in Berlin still has complete 32% and 40% orifice/bypass cups which will permit the Ray to be used deeper than ''original'' factory set up allowed...
It probably won't last much longer but currently W S Water Safety has more new service/replacement parts available for the Ray than for the Dolphin...
Best...
Warren