Analyzers

[Wijbrandus]

Can anyone recommend a good, reliable, and easy to use CO analyzer? I assume there still isn't a device out there that can measure both CO and O2 at the same time.

Thanks for posting this thread. It's a good reminder.

 

[Basking Ridge Diver]

http://www.scubaboard.com/forums/ba...hy-have-co-analyzers-been-removed-market.html

Try this - lots of threads out there - Google is your friend.

 

[Wijbrandus]

Why have a discussion board if "google it" is the answer to everything?

 

[Basking Ridge Diver]

Why have a discussion board if "google it" is the answer to everything?

Generally I use Google to do research - narrow it down - then discuss... because Google is your friend

Kind of like when my kids ask me the meaning of a word - I first say - did you look it up? I find when they get spoon fed they don't remember it the next day - but when they do some work for it - it generally means a little more and it is retained... But better yet they may find another word or thought and find more interesting things - but that is just me.

 

[tamas970]

Thanks for the reminder topic, I am planning a major diving campaign in Egypt and definitely bringing along an analyzer.
Life in Africa is cheap, one should make his own safety precautions...

However, the thing doesn't need to be overdone. 60min emergency exposure level is 400ppm.

A quick calculation: - allow for 100ppm at depth (safety factor 4x),
depth: 30m, time: 60minutes (deco already, even on EANx36...) -> pressure at depth = 4bars

ppCO at surface=100ppm/4=25ppm, the device have to give an alarm below this value.
Most household CO detectors can do that, no need for fancy overseas orders, pricey sensor replacements,
etc.
Saying that, because over here in Europe the Analox device is hard to get/overpriced, I ordered this one with
(T-piece and flow diverter for scuba tanks is available at the manufacturer):
Greisinger GCO 100 Gas meter from Conrad.com
It is not as sensitive as the Analox, but good enough.

Long story short: to kill someone, the air should be really bad - but sh't happens, a CO detector,
even the simple one can save your life. (Even a 20$/EUR household unit, that alarms at 30ppm)

 

[Scared Silly]

tamas970, your logic is off:

http://www.hse.gov.uk/pubns/dvis9.pdf

Most people are not willing to get a headache, feel nauseated, or otherwise be impaired while underwater. That is asking for trouble. Further, people react to CO differently. Further a household detector does not alarm until 50-100ppm. The detector you list above has a range of 0-1000 with a +/-5% range. That means +/-50ppm. Not good enough but better than nothing.

 

[tamas970]

The 5% accuracy for the GCO stands for linearity, absolute error I do not know. However it is used by
doctors to measure exhaled CO for COHb estimation, thus it cannot start from 50ppm...

The thing is, that the only documented death case in Cozumel I know was caused by >1000ppm as far as I remember.

(some more reliable info on 1500ppm in three tanks: http://www.scubaboard.com/forums/ac...s-tank-co-test-cause-death-6.html#post6579993 )
These are definitely lethal at depth and can be avoided with the simplest, cheapest unit - which doesn't help you if you are still in the "planning to get
a CO-monitor and evaluating the various (pricey) options" phase.

Here is another report on the Maldives incident: http://www.mercury.com.cy/documents/Maldives_Fatal_Diving_Accident.pdf - the uniqueness of the event is
that one died (>>150ppm CO in the tank, how much more they could not tell, because that was the upper limit of the test tube), others survived but
got sick (~80ppm CO measured in their tank). I haven't found depth+time (=exposure) infos, all we got that they dived the Raydhigaa Thila reef as a morning
(deepest of the day?) dive.

Some further real-life data on boat-engine (+generator) related accidents: Boat-Related Carbon Monoxide Poisoning
These concentration values are off the scale in the diver's perspective.

Today's standards are set with a broad safety margin.
Of course if you want to enforce the standard, get an Analox, probably the only reliable portable one to measure accurately below 10ppm.
If you just want to be safe, get anything that alarm below 50ppm thus you can avoid those lethal tanks that really cause the accidents.
More important is to have a device and use it (+sometimes test it with some real life sample, e.g ask a smoker to blow on it,
it should show a value above 10ppm - if you see the same or worse reading from your tank, that's a good reason to return).

 

[DandyDon]

I fixed the above for you. As a cave diver, please make sure you know the differences between O2 and CO, and Nitrogen vs. Oxygen. I am sure it was just a mistake, we all make them.

Yes, and online discussions carry so much impact, with portions showing up on google searches. If you cannot be accurate with your use of abbreviations, acronyms, and symbols - then spell out the terms: Oxygen, Carbon Monoxide, Nitrogen, etc. That first post made me dizzy but left as it is, could show up on google searches.

Ok I will confess that I thought it would never happen to me in the US.
Well it did!
My buddy got it worse and thankfully no lasting ill effects.
THIS IS NO JOKE!

If you are diving you need to not trust your fill station!
I know the fellow we got gas from and he is a great guy no malice or bad feelings at all.
It was compressor issue, I had one myself earlier this year with mine.
YOU CAN NOT AFFORD TO NOT ANALYZE YOUR GAS FOR CO2!

Please heed the warnings it is such a preventable issue!

CamG

However: If you cannot be accurate with your use of abbreviations, acronyms, and symbols - then spell out the terms: Oxygen, Carbon Monoxide, Nitrogen, etc. You don't need to test for Carbon Dioxide.

Can anyone recommend a good, reliable, and easy to use CO analyzer? I assume there still isn't a device out there that can measure both CO and O2 at the same time.

Thanks for posting this thread. It's a good reminder.

Sensorcon but there are others that cost more.

Thanks for the reminder topic, I am planning a major diving campaign in Egypt and definitely bringing along an analyzer.
Life in Africa is cheap, one should make his own safety precautions...

However, the thing doesn't need to be overdone. 60min emergency exposure level is 400ppm.

A quick calculation: - allow for 100ppm at depth (safety factor 4x),
depth: 30m, time: 60minutes (deco already, even on EANx36...) -> pressure at depth = 4bars

ppCO at surface=100ppm/4=25ppm, the device have to give an alarm below this value.
Most household CO detectors can do that, no need for fancy overseas orders, pricey sensor replacements,
etc.
Saying that, because over here in Europe the Analox device is hard to get/overpriced, I ordered this one with
(T-piece and flow diverter for scuba tanks is available at the manufacturer):
Greisinger GCO 100 Gas meter from Conrad.com
It is not as sensitive as the Analox, but good enough.

Long story short: to kill someone, the air should be really bad - but sh't happens, a CO detector,
even the simple one can save your life. (Even a 20$/EUR household unit, that alarms at 30ppm)

If I was going to Egypt, I'd want two: My Analox and my Sensorcon, but then I take those to Cozumel. I wear the Sensorcon everywhere, and I have had some alerts in my day to day life in Texas.

Your logic lacks so much. I don't guess you have any medical or technological training in this area? Better to stick to the standards developed by those who do as it's a lot more complicated than you suggest. And your cheap home unit that alarms at 30ppm has to have like an hour exposure to do that. Leave it in the bedroom.

tamas970, your logic is off:

http://www.hse.gov.uk/pubns/dvis9.pdf

Most people are not willing to get a headache, feel nauseated, or otherwise be impaired while underwater. That is asking for trouble. Further, people react to CO differently. Further a household detector does not alarm until 50-100ppm. The detector you list above has a range of 0-1000 with a +/-5% range. That means +/-50ppm. Not good enough but better than nothing.

Thanks.