“Home made” CO Tank Testing

Dear George,

There have been two scuba deaths recently due to contaminated breathing air. We are still not sure if this was from CO alone or in combination with CO2. Official reports still pending. As a result of this many in the diving community are reexamining their risk of exposure to CO in tank air and what can be done to minimize this risk.

Your detector given its accuracy in the low ppm range and very favorable price point seems to be the ‘weapon’ of choice so far amongst the divers. I have been using mine without problems for a year now by just putting the detector in a bag but most would like a detector where one can attach the detector directly to the air source and not have to worry about ambient air in the bag.

One bright fellow has done just that and thought you might be interested in his handiwork. The flow restrictor and cap are available from www.oxycheq.com so the modification is quite easy and cheap. http://www.denninger.net/diving/co-analyzer.htm If you have any thoughts on this modification good or bad send them to me and I can post them to the scuba discussion group with your permission of course.




P M,A “Unique” application for C  O – Experts; however, I think that another
version of my unit that is in R & D may prove to “Adapt” to this problem
even better. It is a “Hand-Held” Portable Model with a “Breathalyzer”
attachment, that would provide “Easy Access” to the Sensor area, and give
readings from 1 to 70 PPM.

Best Regards, ………………….. George


Those two deaths in Mexico from bad tank air have compelled this genteman Karl Denniger to do something about it. He is quite the activist and I applaud his efforts. He is actually suggesting the scuba fill stations purchase one of your units and bleed off the fill whips at a flow of 1 lpm a continuosu stream into a CO Experts unit. In regard the diver will know that the air is CO free.
Otherwise a shop is looking at purchasing an inline high pressure analyzer from these guys for about $4000 US.   www.nyad.com
Maybe you should look more closely at modifying access to the detector for this use?
You might want to contact Mr. Denniger as he is much more familiar with all the technical issues of high pressure gas fittings and flow restrictors for diving and I think would be quite interested in this project. Would you like me to contact him for you first?




Hi George,

I have given Karl your email and tel. number so you should hear from him next week. He is still very keen on your product despite several others being mentioned for scuba use. He has also recommended your unit for boat use.

The only ‘dedicated’ scuba CO monitor on the market from www.oxycheq.com for $330 has one big disadvantage other than price which is the sensor life is only 12 months! It is housed in a unit identical to their Expedition Oxygen unit (see attachment) and I suspect has a Teledyne sensor unit. No mention of what the sensor replacement cost would be.

A very interesting but too expensive unit at $1000 is this Bedfont Micro III unit for CO in the breath. The ToxCo is about the same price without a case.

I really think if you can make the white sensor cap from oxycheq with the flow restrictor (total cost $30) easily fit onto your unit then we have a winner. The only issue will be calibration as people will want to know if the unit is reading accurately before testing their breathing gas. This is quite a demanding application. What sort of stability is there on the unit once calibrated?

I don’t think the owner of Oxycheq  is going to sell many units at that price and sensor life. He may just want to sell your product instead!!


Return to ‘Air and Oxygen Tanks’     Back to the Main Page



CO Experts
19299 Katrina Lane; Eldridge Missouri 65463-9102
Tel: 1-888-443-5377 Fax: 1-888-436-5377