Do get a co analyzer or not?

[markmantei]

The dive agencies (and DAN) aren't interested in championing the cause of contaminated air--it may be due to financial considerations, I don't know, but the subject doesn't get more than a passing mention. So you won't find a lot of documentation about it, other than what you read at the grass roots level (us) about "being on a boat and the tank tested bad."

Which is sad because the dive industry gets it when it comes to nitrox, where analyzing and reanalyzing your air is drilled into divers as part of diving procedure.

Maybe that has to do with the fact that nitrox is a course, and their is money to be made in teaching the use of alternative gases, selling analyzers, etc to divers who want to further their education and extend their diving. Testing air would need to be taught to all divers, education would mean increased costs for (some) fill stations/dive ops/lds (those that do not already have inline monitoring/testing equipment), and may potentially scare off some potential divers/clients, those who just want to be told that scuba is safe and you don't need to worry about a thing. Then again maybe I'm just being cynical.

 

[DandyDon]

Great discussion here. This is a special subject for me tho so I'd like to add some thoughts if anyone is still reading...

A diver buying contaminated air any where is bull **** and you should not have to test your air for CO any more than you have to test your food for arsenic.

If you folks really believe this is an issue, we should petition our worthless dive agencies demanding proper self regulation or threatening govt oversite.

If it is not really a problem and some are just suffering from OCD, that is another issue.

It is a real problem. DAN admits that they don't know how many drownings may have been from CO hits as the bodies are seldom tested for carboxyhemoglobin. Whether the local facilities lack the capability or the local businesses don't want to allow bad news for the location is a matter of opinion. Then there are non-fatal hits as well as sub-clinical hits that are generally shrugged off as Travelers Flu, but we just do not have a good idea of how big the problem is. The industry developed before CO testing in low range was possible, and only now are we changing old habits of blind acceptance.

vladimir I would agree to a point with your answer. However, I am a boater and never get sea sick, I am also a pilot and had no ear problems flying down there or on the days after my dives and also I could "taste" the air and it tasted stale. I am trying to use this experience as a lesson in case I did experience carbon monoxide in my air so that it will not happen again. Thanks.

Tasting anything in air is a sign to reject the tank, but hard to say what was in yours. Your experience really could have been motion sickness; you probably never get it when you are piloting the plane or boat, but how often are you a back seat passenger? Still, you don't know either way unless you test the tank yourself, preferably before diving it.

Last I checked, the Analox Ell CO monitor was going for about $360, in case anyone is interested.

It has gone up a few bucks hasn't it. I am curious as to how their sales are doing as the more divers who get involved the better. If one cannot turn lose of that much, the Pocket CO tester does work. I had to replace mine after dunking the first one and the new model will pick up as low as 3 ppm, I know - altho I use it only for comparison to my Analox CO. The Pocket CO has to be kept inside the ziplock as humidity gives false readings, and it takes 3 minutes a tank to test, but otherwise it works well for about half as much. I do not like the special zip lock they developed tho. I use a slider one gallon zip lock and take several bags as they wear out quickly.

I don't think the dive community at large is knowingly accepting that they're being poisoned, they're just unaware it's happening.

Before the CO problem can be addressed, it first has to be acknowledged, and we're currently in the "denial" stage with a few informed divers trying to increase that awareness.

Yep, right on.

I was going to add: how can ANYONE say it isn't/doesn't happen when no one and no agency or dive op tests every tank they get......it could happen far more often and the divers/DM's may never even know if it is low level CO and not enough to seriously injure or kill anyone. Then again.....how many mysterious deaths happen in Coz that are not 100% explained/investigated/solved? Is there a policy to test EVERY tank involved in a serious dive accident or death? I highly doubt it..... (hope they do)

The only way to 1) know 2) make sure is for more Ops and people to test more tanks. Show me that no one gets high readings and I will then believe it never happens. Until then, I will assume it COULD happen and is in the realm of possibility.

In the US, yeah, I would seriously doubt it would ever happen. But outside the US......possible for sure.

Yeah, it happens in the US, just not as much. Coz has had several CO hits in recent years, but while actions are being taken by many to improve the situation - I test all tanks, everywhere.

Maybe I just read the last line since that is the one I was addressing. As already mentioned Aldora jumped into action, because Dave knew of the potential for a problem and didn't want to see a customer on Cozumel be injured from something that is preventable. Modern technology allows these tests to be performed for reasonable costs today. I would bet the other dive ops are happy to hear CO meters are being installed, and may well have helped in the push to have them installed.

If I knew my air was tested by a reliable CO meter at the pump, I wouldn't worry about testing each individual tank.

Even some Analox Clear monitors are installed without auto-cutoff, and there are other ways that monitors can miss. Like I said, all of my tanks will be tested by me.

Permissible limits?
aside from the whole question of individual testing, what do you do with the results?
I am having a hard time getting a clean answer on what permissible CO limits are for diving. A quick wiki search shows OSHA long term exposure limits at 50 ppm, DAN indicates that ambient air can be 10 ppm (Alert Diver cites CGA, ANSI). Several posters note concern over 15-20 ppm readings.

What reading would cause you to reject a fill as an unacceptably high CO Level? 10 ppm? 20 ppm? higher?

Do you have different threshholds for repetative dives or different depths?

I know divers who will not dive a tank at 3 ppm or more. I'm a little more flexible in accepting a 10 ppm tank once, not as a common thing. We did dive those 17 ppm tanks on a shallower dive that day, but we should not have. I keep learning. :blush:

yup to everything you just said. It will be a painful and awkward transition while the frequency of testing increases and the question of "what to do" in that scenario arises more and more often. In a year or two-hopefully sooner-I bet we won't even need to ask this, because the standard will evolve according to sense, both common and fiscal. Which dive ops will survive if they refuse to "be against" their divers diving with bad air, when there are other ops that accomodate the new standard?

Yeah, with the exposure of past problems, more divers testing, more stations monitoring, and DAN supplying some free units to the island, I agree - the risk will become even more remote. Would that be a time to relax and stop testing? Nope. Many of us dive other locations and need the tester anyway, but whatever - I never know the history of the tank or fill, so I check.

Interestingly, I have yet to have someone else on a dive boat ask me to test their tank when they ask about my monitor and why I am testing.

Me neither. They seem to think that if my tanks are ok, theirs must be - a common mistake.

Maybe that has to do with the fact that nitrox is a course, and their is money to be made in teaching the use of alternative gases, selling analyzers, etc to divers who want to further their education and extend their diving. Testing air would need to be taught to all divers, education would mean increased costs for (some) fill stations/dive ops/lds (those that do not already have inline monitoring/testing equipment), and may potentially scare off some potential divers/clients, those who just want to be told that scuba is safe and you don't need to worry about a thing. Then again maybe I'm just being cynical.

Yep, but our money still demands actions. If we spend a little to test, then take the rest of our money elsewhere when we are not happy - our money wins.

 

[markmantei]

I know divers who will not dive a tank at 3 ppm or more. I'm a little more flexible in accepting a 10 ppm tank once, not as a common thing. We did dive those 17 ppm tanks on a shallower dive that day, but we should not have. I keep learning. :blush:

Don, I'd like to hear a little more about your 17ppm experience. What kind of depth did you attain on that dive and for how long? Did you notice any ill effects during or post dive?

 

[DandyDon]

Don, I'd like to hear a little more about your 17ppm experience. What kind of depth did you attain on that dive and for how long? Did you notice any ill effects during or post dive?

I'm sorry. It's been too long and I don't keep detailed logs. Suprane might have more info.

We were headed to dive Cathedral, after getting a lot of 7 ppm readings that week, checked on the way, found 17 in 6 tanks and stopped checking - telling the crew we would not dive deep on those. We turned the boat and did a couple of shallow dives with no problems. But then effects of marginal CO loading can vary.

Suprane double checked his analyzer when he got home and it was on the money. If you can't take the word of an anesthesiologist, well. I later replaced my Pocket CO and got my Analox CO, then loaned the latter to Suprane for his Barbados trip but he got nothing on either his or mine there. I got nothing on my last Coz trip, commended the Op as it was the same one, and she said she was using a different filler.

That's another thing. You may be diving with an Op using a clean filler then one day tank deliveries are delayed, so they might borrow from friendly competitors. If you don't fill your own tanks, you don't know the history.

 

[cruiser]

It would take lot of CO poisoning to make it a significant risk.

What level of contamination would you consider a significant risk? 5%? 15%? Or more?

 

[Ron Lee]

What level of contamination would you consider a significant risk? 5%? 15%? Or more?

This may be more useful as a PPCO (partial pressure of CO) type number where you take the surface CO PPM and multiply by the atmospheres at depth...if depth is a factor. Assume about a 5-10 minute exposure.

 

[cruiser]

Maybe that has to do with the fact that nitrox is a course, and their is money to be made in teaching the use of alternative gases, selling analyzers, etc to divers who want to further their education and extend their diving. Testing air would need to be taught to all divers, education would mean increased costs for (some) fill stations/dive ops/lds (those that do not already have inline monitoring/testing equipment), and may potentially scare off some potential divers/clients, those who just want to be told that scuba is safe and you don't need to worry about a thing. Then again maybe I'm just being cynical.

I think you're being realistic, which is sometimes the same thing as being cynical.

Beginning divers generally believe that scuba is safe and you don't need to worry about a thing. Advanced education and training, however, makes you realize how much you DIDN'T know as a newby. It would be advantageous for divers to get structured info about contaminated air before taking tech classes.

 

[Mike]

I'm sorry. It's been too long and I don't keep detailed logs. Suprane might have more info.

We were headed to dive Cathedral, after getting a lot of 7 ppm readings that week, checked on the way, found 17 in 6 tanks and stopped checking - telling the crew we would not dive deep on those. We turned the boat and did a couple of shallow dives with no problems. But then effects of marginal CO loading can vary.

Suprane double checked his analyzer when he got home and it was on the money. If you can't take the word of an anesthesiologist, well. I later replaced my Pocket CO and got my Analox CO, then loaned the latter to Suprane for his Barbados trip but he got nothing on either his or mine there. I got nothing on my last Coz trip, commended the Op as it was the same one, and she said she was using a different filler.

That's another thing. You may be diving with an Op using a clean filler then one day tank deliveries are delayed, so they might borrow from friendly competitors. If you don't fill your own tanks, you don't know the history.

Hey Don, if you have the inclination, I know I'd be interested in knowing more of exactly how a person goes about testing with one of these units you own, basically a how to guide from your personal experience, the steps you take, how you zero out the thing etc...

It would be very informative. You could even start a new thread and basically give an insider view to everyone else exactly what it takes to test your tanks, any details you have discovered, short-cuts, etc..

I think one of the things that holds a lot of people back who are on the edge is the confusion about how hard it is to actually do or not, and especially the time and costs involved in costs and maintenance on one of these units. Don't some of them have to be sent back to the manufacturer for calibration from time to time?

 

[DandyDon]

Hey Don, if you have the inclination, I know I'd be interested in knowing more of exactly how a person goes about testing with one of these units you own, basically a how to guide from your personal experience, the steps you take, how you zero out the thing etc...

It would be very informative. You could even start a new thread and basically give an insider view to everyone else exactly what it takes to test your tanks, any details you have discovered, short-cuts, etc..

I think one of the things that holds a lot of people back who are on the edge is the confusion about how hard it is to actually do or not, and especially the time and costs involved in costs and maintenance on one of these units. Don't some of them have to be sent back to the manufacturer for calibration from time to time?

Oh, it's too easy with the Analox Portable CO analyzer really. Ever used their portable Nitrox analyzer? If not, see How to use an Analox O2EII Nitrox diving analyser - YouTube

(1) Push the button to turn it on, remove the dome to expose the sensor to air, turn the dial to calibrate it to zero, and replace the dome. No need for temperature and humidity adjustment like with the Nitrox unit tho.

(2) Bump test it to make sure it's working. They sell a small can of weak CO which is allowed to fly on most airlines, but I just blow into it for 5 seconds as everyone's breath has a little CO. For bigger results, get a smoker to blow into it. Either way, there should be a few digit change in the screen.

(3) Crack the tank to let just a little escape, press and hold the sampling dome firmly against the tank outlet for 30 seconds, and if you see zero - good to go. It'll auto turn off after a few minutes of non-use to conserve the battery so just put it away.

(4) If you see digits appear in the screen, push the power button once to freeze it so it won't vanish when you move away from the tank, show the reading to your Op, and discuss the value if it's over 3! Whether you dive a tank at 5, 7, 9 or whatever is a personal call.

The manual is actually an easy read, nothing like dive computers. See http://www.analox.net/product-docs/manual-91.pdf

Opinions still vary on calibration. The manual says to do so every six months or before a trip, while the official word has changed to "never mind" since you can use the calibration knob and bump test. I am doing annual calibrations at the company for now, that is this spring, but I might not next year.

The test should be done before boarding or at least before starting up as engine fumes can throw off calibration, especially on bigger boats with a cabin and the station wagon effect. Additionally, I would not calibrate & test on the street before going to the dock as street fumes and throw you off.


Well, you could go with the Pocket CO for half the money, but you need to keep it in the ziplock for the entire trip as it is vulnerable to false readings from humidity and other environmental factors. They have a Scuba kit with everything for $200, but really - I disliked their special bag. Just get the basic 300 model for $139 and the calibration gas for $39 as they do recommend semi-annual calibrations for low range testing. I like slider gallon ziplocks for ease of handling and take several as they seldom last more than a day, carrying a spare in my dry bag.

1: With the unit inside the bag, turn it on, let it run self test, and see that it reads zero.

2: Crack the tank, fill the bag,* close the bag & tank, and start your timer on your watch - waiting 3 minutes before reading.

3: If 3 ppm or less, empty the bag, turn off the unit, store in dry bag. If more than 3, your call. If more than 10, don't be foolish.

* Do not hold the bag to the tank as you crack it open! That is how I sent mine flying overboard. :silly: We turned the boat and retrieved it floating, but just a little water got inside and it was ruined. Again, best to test before leaving the dock really, but you still don't want it to go overboard.

Ok, here is a hint: How do you keep up with your tank after testing if it rides in the back of a panga with the others, and the DM wants to put your BC on for you to avoid having tourists walking around while the boat is underway? You know those free envelope return address labels you get from the Audubon society every year, or similar? Carry a supply in your dry bag, stick one on the tank under the valve outlet, and show the DM that it is your tank. Remove before you go in, or if you miss that step, they're tiny, biodegradable and should come off in salt water.

 

[cruiser]

DandyDon--

Do you replace the battery in your Analox CO analyzer every year?