I'd like to do it on the dock too, but on Grand Cayman when I was there, the tanks were already aboard the boat, and you just chose one after the boat left the dock.
That brings up another question. Shore dives - I could sure test the tank on shore before I get into the water, but what's to keep the EII CO from growing legs and walking off after I get in the water? Another conundrum.
I think your point about the way the EII CO samples from the tank is a good one. Hopefully, that low pressure stream from the tank valve would tend to keep outside air from contaminating the reading....hopefully.
Yeah for tanks on the boat, take some sort of sticker or tape so you can test tanks then put your name on them. I get so many return address stickers from charities wanting me to send money every year. DAN even sent me some. Or yellow electric tape, which is also usual otherwise in a safe a dive kit, or masking tape - write your name on it. For shore dives, test the tanks when you pick them up, put your name on your tanks, then leave the analyzer someplace safe. If you dive Nitrox, you do the same with it and the analyze.
OKAAAAY, I finally got to town, for my new Analox portable analyzer, played with it some, talked with Patti on the phone twice I think to clarify some things - such a nice lady
, and I've corrected some of my thinking I think.
I had thot one might use the 10 ppm bump gas to test their analyzer for accuracy, but nah! Maybe Surpan does with his 17 liter tank, but that's not the reason Analox offers it for sale. It's just to confirm that the analyzer is still working; the accuracy comes from proper calibrations.
SO YOU DON'T NEED BUMP GAS, IMO! If you want it, fine, Analox will supply it or you can order 10L or 17L tanks where Suprane got his, but it's really optional. Just blow on it, or if you want bigger results, get a smoker to blow on it - no he does not need to be smoking at the time as his exhale will stay tainted for a long time.
The breath concentration in a non-smoking individual in CO-free ambient air can be as high as 4 ppm. I know mine runs consistently at 2 ppm and my secretary who smokes runs at 9 to 10 ppm.
To use the EIICO for breath CO analysis take a deep breath and gently blow into the larger hole on the "side" of the sensor dome rather than the pin hole where one flows the compressed air into. It is quite interesting how stable one's breath CO concentration is as long as not sick (i.e. a cold) or walking around in a room full of smokers.
Our body produces and releases carbon monoxide, hydrogen sulfide, and nitric oxide all of which are gaseous neurotransmitters and can be measured in the breath.
And while calibration twice a year is nice, we're not pathologist getting ready for a trial. Once a year is probly fine, unless you ask Analox lawyers...
I think the sensor has a 6% annual drift so if you did not calibrate for a year, it might read 15 ppm as 14 or 16 - close enough to get excited.
14, 15, 16 - you don't want to dive it anyway. Since it rounds to nearest parts per million, and that is such a tiny amount numerically, you might see 4, 5, or 6 in another example. Ideally we don't want to dive that either, but - your call on accepted risks in diving.
I'm keeping my Pocket CO and Analox CO in Pelican cases so they can't be exposed to city air as I have seen some 10 ppm readings at airports and in cities myself. For that final pre-test calibration, yeah you want to be in clean ocean air or similar - maybe on the upper deck of a large boat if the wind is favorable, or whatever it takes.
