O2 Analyzers

[Octopusprime]

I have always realized tanks at the shop when picking them up but now that I have 10 tanks and one may sit for an entire summer to the spring and I want to get into the habit of testing them again before the dive or at least when packing the car before a weekend of diving. Almost every shop I have been to use the analox O2EII and it works fine andI'mm sure I can get a small hard case to protect it but when you have a bunch of tanks in the back of the truck I like the idea of some of the ones with a hose.

Also, I think it is ODD that you have to calibrate them by putting them on a tank. If you set it to 21 from a tank that has 32 percent you will have a problem. I have seen some analyzers people wave around to circulate air. There seems to be a lot of options in the $250-300 range then a BIG jump to $700. Any suggestions?

Also since I always get my tanks filled form LDS that regularly gets compressor tested by independent service do I need to worry about a CO2 tester? I am starting Tec diving but do not see going to Trimix anytime soon.

 

[JohnN]

I have always realized tanks at the shop when picking them up but now that I have 10 tanks and one may sit for an entire summer to the spring and I want to get into the habit of testing them again before the dive or at least when packing the car before a weekend of diving. Almost every shop I have been to use the analox O2EII and it works fine andI'mm sure I can get a small hard case to protect it but when you have a bunch of tanks in the back of the truck I like the idea of some of the ones with a hose.

Also, I think it is ODD that you have to calibrate them by putting them on a tank. If you set it to 21 from a tank that has 32 percent you will have a problem. I have seen some analyzers people wave around to circulate air. There seems to be a lot of options in the $250-300 range then a BIG jump to $700. Any suggestions?

Also since I always get my tanks filled form LDS that regularly gets compressor tested by independent service do I need to worry about a CO2 tester? I am starting Tec diving but do not see going to Trimix anytime soon.

Your worry should be CO (Carbon Monoxide) not CO2.

Although their customer service is "spotty", I have a COOTWO and like it and I would buy another. As for calibrating it on the tank, yes the O2 sensor is effected by moisture and temperature, but diving with Nitrox is not black and white. There is no good science to say that a PO2 of 1.4 is safe and 1.5 or 1.6 will kill you, it depends on you and the dive conditions.

O2 analysis for diving is a bit like "Measure with a micrometer, mark with chalk and cut with an ax"

 

[nadwidny]

I
Also, I think it is ODD that you have to calibrate them by putting them on a tank. If you set it to 21 from a tank that has 32 percent you will have a problem. I have seen some analyzers people wave around to circulate air. There seems to be a lot of options in the $250-300 range then a BIG jump to $700. Any suggestions?

Also since I always get my tanks filled form LDS that regularly gets compressor tested by independent service do I need to worry about a CO2 tester? I am starting Tec diving but do not see going to Trimix anytime soon.

I work with O2 analyzers in the lab that cost around $10K. The daily calibration is done "waving them around to circulate air" (not really. They have pumps which draw air in but same thing.)

CO, not CO2.

 

[tc]

You might want to check with your local shop, if they already have an inline CO analyzer then you shouldn't need one for the tanks filled there.

 

[soonerwink]

You might want to check with your local shop, if they already have an inline CO analyzer then you shouldn't need one for the tanks filled there.

That is not entirely correct, you should at least witness the analyzing test if you aren't allowed to test it yourself. Some shops don't like outside divers other than employees to use their expensive analyzers.

 

[tc]

I’m talking about an line analyzer built into the compressor output, not a portable analyzer.

 

[NAM001]

You dont need an expensive tester. I have an ElCheapo by oxycheq and it works fine. costs perhaps 150 with all the bells and whistles and you make it at home from a kit. as far as calibrating it from a tank. I prefer that because waving it in the air has errors caused form humidity and you have to correct for it. (loose use of have to) if you use a tank of known content then it is dry air ,,and the cal will be right for any other tank you test. If you are not the electronic type, then this may not be the right path for you. Still having a say 3 cu ft tank of sample gas is a good idea but far from necessary to have useable numbers to set your computer with.

here is a link to the testerat oxycheq..

OxyCheq - EL Cheapo II Analyzer Kit

i have been using it since 2003. make sure you get teh 10 turn pot and not use the one turn one that comes with it.
The correction chart if you choose to use one you will have to hunt to find. I can send you a copy of mine if you want. Much easier to use a sample tank with a known content of anyting solong as it is known. 30% is fine and pretty central in range of the nitrox you will be using. the ipurtant thing is using a dry sample gas to cal with and then checking dive gas that is also dry.

 

[Pkishino]

Our build your own the only expensive part is the cell anyway. Waterproof case induction charging, arduino, small LCD and you can build a cool analyser for way cheap. Works great.

 

[soonerwink]

You might want to check with your local shop, if they already have an inline CO analyzer then you shouldn't need one for the tanks filled there.

You still have to be able to check your tanks even with an inline analyzer.

 

[tursiops]

The correction chart if you choose to use one you will have to hunt to find.