Update: Now I Have a Personal Carbon Monoxide Monitor/Tester

[Tom Smedley]

Don

What about a methane tester???

 

[DandyDon]

Don

What about a methane tester???

I don't know, do you think there is a risk in this area separate from CO? Fill Express has published a lot about gas qualities: From Fill Express -- Quality of Breathing Gases

Total Volatile Hydrocarbon Content -- Breathing hydrocarbons can interfere with oxygen intake, and short-term exposures are associated with mucus membrane irritation, nausea, vomiting, diarrhea, and confusion.

Several thousand types of organic gases and vapors can potentially be present in Air. Volatile organic contaminants can be manmade (e.g., gasoline vapor, exhaust fumes, cleaning solvents) or from natural biological activities (e.g., methane from organic decay). Because it is impractical to measure each type of organic contaminant present, they are measured as a group described as a Total Volatile Hydrocarbon Content (TVHC).
25 ppm Allowed maximum for CGA G-7.1 Grade "E"
Less than 1 ppm Test results for Fill Express gases, excluding methane

Those symptoms do not sound fun at all, but not as deadly as CO poisoning. There are testers economically available LCM DIRECT INC 240PGD GAS DETECTOR HAND HELD but while the methane and other possible volatile organic contaminants of a faulty compressor would be a serious problem, I'd be more worried about dying from the CO from the same compressor I think.

But then I'm no scientist, not the person to ask probly. I'm just a little bent about what seems to be the biggest flaw in our overall safety program...

• Train, practice, and dive for safety;
• Invest in safe gear and service it as indicated;
• But breath anything out of a compressed scuba cylinder...?!

 

[swamp diver]

Don

What about a methane tester???

Methane is generally considered non-toxic and is a simple asphyxiant which would require a concentration of about 5 percent or 50,000 ppm to produce hypoxia.

The lower explosive limit (LEL) for methane is also 5 percent and generally NIOSH limits exposures to 10 percent of LEL in order to minimize any potential toxicity concerns. This would represent a concentration of 5000 ppm.

Normal ambient methane levels are 1.7 ppm and the maximum a compressed breathing air laboratory might see is in the ballpark of 300 ppm so methane is a compound you generally do not need to worry about as a diver. As you will notice CGA Grade E air does not have a specification for methane.

The total volatile hydrocarbons are a real concern for divers since many of these compounds are narcotic. They are measured in Grade E air but unfortunately there is no reliable low-cost detector available on the market which could be used out in the field. A decent field detector for TVHCs will run about $2000 plus calibration gear. The second best detector for these compounds is your nose. Smell each tank before using it and if an unknown odor is detected do not dive the tank.

 

[mrlipis]

Note: Due to recent high demand, your order may be backordered 2-3 weeks.

Look what you've done Don. Just copied that from their website.

Bruce

 

[DandyDon]

Note: Due to recent high demand, your order may be backordered 2-3 weeks.

Look what you've done Don. Just copied that from their website.

Bruce

Oh, there were many waiting on the new Model 300 to come out I think. I sent an email to the address on the Support page pocket_support@kwjengineering.com advising of an approaching trip (actually my Instructor's trip) and they expedited my order. Ordering a full month in advance of one's next trip would be prudent, tho.

I see where they've added the small 1010 Pelican box to their options - at a surprisingly high price of $25?! LP has them for $8.42 Pelican #1010 Micro Case from LeisurePro.com I asked Oliver about that; he agreed it was not a competitive price in the US - aimed more at European needs.

I have yet to actually see mine; it should be back from Utila with my Inst and I'll pick it up this weekend. I think it might fit inside a tiny, waterproof cigarette box.

 

[DandyDon]

Talked with the LDS who borrowed my tester for their trip last week. See http://www.scubaboard.com/forums/ne...ide-levels-discovered-utila-nitrox-tanks.html

 

[Chriskat]

Since the unfortunate death aboard the Baani Adventurer, and as my wife and I had spent a week on that boat in August last year, I have been paying a lot of interest in your threads regarding CO testers. I have found a tester in the UK with a 5 second response time and weighing only 3.5oz (100grams). It costs a little more at £135 ($270) and I have no info other than that available on their webstite and I thought that with your experience investigating this type of equipment you might like to take a look and let me have your opinion.
Anton Spygas CO and Anton Spygas combustible Gas Detectors - Carbon Monoxide Detectors - Safelincs.co.uk - your safety provider

 

[DandyDon]

Since the unfortunate death aboard the Baani Adventurer, and as my wife and I had spent a week on that boat in August last year, I have been paying a lot of interest in your threads regarding CO testers. I have found a tester in the UK with a 5 second response time and weighing only 3.5oz (100grams). It costs a little more at £135 ($270) and I have no info other than that available on their webstite and I thought that with your experience investigating this type of equipment you might like to take a look and let me have your opinion.
Anton Spygas CO and Anton Spygas combustible Gas Detectors - Carbon Monoxide Detectors - Safelincs.co.uk - your safety provider

I am not expert, but I will offer some observations - and hope others will too...

It's an interesting instrument, may work work very well in some situation, in fact - the 10" length may be very helpful in some work. That you can have it serviced inside the UK is a plus to be sure. The 5 second response time is impressive, but I'm not sure what they mean by 20 second Stabilisation time. Really, I'd suggest you phone them and ask: "If I hold this to an air stream, how fast will it give me an accurate reading?" 20 seconds is a bit long to bleed air off of a tank, and the one I use suggests 90 seconds for accuracy so I close it up inside a clear bag that I fill from the tank. If you had to do that, the 10" would be a challenge. From reading more into their Technical Specifications, they suggest a 15 minute wait for Ambient CO Room (air)Test, but you may learn more from chatting with them.

It's not one to leave on all the time like I use mine. AA batteries are cheap, or they are here, but I wouldn't want to replace them every other day - or have it clicking constantly. It's an instrument to turn on and off, and I prefer to use mine for the second purpose of 24/7 monitoring. *

And they all have to be calibrated annually. Do you have to return it for that, and how much does that cost? I can calibrate mine myself with a $39 "small canister of CO that has been heavily diluted with air, making it harmless," it contains enough for 3 calibrations, and since it must be used within a year, I expect that I can calibrate from it twice in 12 months - then in 2 years, see if there's something better out?

Finally. $139 plus shipping to the UK is still only a litlle over half what that one costs, and mine fits in the palm of my hand.

Hope that helps, but - if that one works out for you, great. I see they operate in the US, but do not offer that.

* I'm still searching for a portable CO monitor suitable for an automobile. A freind found one, but the company is not operating. The others we've found are designed for RVs and planes, really a bit bulky for a car.

 

[Geoff_H]

I wonder how many scuba tanks are filled and used every year, and how many deaths could possibily be attributed to carbon monoxide poisoning? Even assuming every scuba drowning death is CO-related would still give a tiny figure I think - in the odds of one in a million.

Anyone have any estimated figures on number of tank fills and number of deaths per year?

I think teaching all divers to carry and learn how to shoot an SMB might be a much more cost effective way to prevent injuries and deaths (being run over by boats, being left drifting by the pickup boat etc).

 

[Scott M]

Don,

Great topic and investigation skills. This has been an issue I have wondered about for quite a while for a few reasons.

On my check out dives with a local shop I felt excessively tired after each and every tank I dove from that shop. I have never had an issue since except one time again when a buddy had his tanks done there, same results. To my knowledge no one was ever harmed from the air and maybe it's just me but while taking a good look at the shops compressor setup. Which was located in a small shack away from anything that might contaminate the incoming air. While there I noticed an odd situation, when the wind kicked up just a little you could smell the exhaust from the compressor, so I walked around the side of the building where the intake was located and sure enough the odor was overwhelming. In my opinion what was happening was under certain sitatutions the wind was carrying the exhaust to the intake side. I know this should be taken care of by the filters but if the filters where towards the end of their life expectency or maybe left in a little longer than they should have I guess it is possible. I discussed it with the shop owenr who kind of blew it off but I noticed they do very little filling from that setup anymore and use their other shops most of the time now.

You have been around here long enough to rememeber Carl, who brought up this subject quite often. He raised a lot of arguements for the use of something like this which if memory serves he took a pretty good beating for back then. His arguments where strong and had me thinking about it ever since, not to a point of obsessions but occasionally if I do not feel quite right after a dive it comes to mind.

Thanks for doing the research, I will be getting one of the testers for sure.

Regards