Use your CO analyzers

[DandyDon]

"Bla bla bla" - sorry if I went on a bit, I am not trying to come across as a know it all as I certainly do not. I'm just interested.

What makes you test for CO and only CO? In the testing I've done it is often the other gases that are different to what they should be- something like h2s is far more toxic than CO and CO2 is a huge risk

I know about the CO risks, so I test. I do not know about the h2s you speak, and CO2 is not a hidden poison that can injure or kill before you notice. It takes a huge change in CO2 to be dangerous, and you'd notice it much sooner. I do also check for O2 even on air tanks, mostly for other reasons, but if there's 20+%, then CO2 is not a risk.

 

[Murky NZ]

How do you do that on the boat in Cozumel?

using a 5 gas instrument. Same theory as a single gas but has 5 different sensors. The same sort of equipment is used both for sampling confined spaces prior to entry and motoring incubators and decompression chambers etc.

 

[Mossman]

And don't forget plutonium. Nasty stuff to inhale. I bring a portable scintillation counter on the dive boat to use after I'm done analyzing the tank for O2, CO, CO2, H2S, N2O (you never know when a dentist last used the tank), and noxious CH4 (what do those guys at Meridiano eat while they're filling the tanks anyway?).

Sure, there aren't any reported plutonium inhalation scuba diving deaths in Cozumel, but that only means "they" covered their tracks well.

 

[Murky NZ]

Ok guys I will leave it at that, I was hoping to ask some constructive questions and learn something myself. If I passed on any info in the process it would be a bonus.

Minimum legal requirement when entering a confined space is to measure for the standard 4 gases. I would personally think the risks in air quality are worse when under water.

I think if you can measure CO and O2 accurately then you're probably doing better than most. FYI CO sensors are cross sensitive to VOC's so sometimes you may not be picking up CO you may be picking up something else but either way you are on the safe side of the fence.

Anyone interested can pm me, I will stop filling this forum with my useless info.

Cheers and and safe diving to all

 

[WheelsUSN]

Your info isn't useless if you can explain to us how you expect those contaminants to enter the tank. I have already mentioned a possible source for CO contamination in an earlier post. How do you think CO2 and H2S would enter the tank and how likely is that to happen? There is a big difference between a tank that shouldn't contain any foreign objects and is dry versus an enclosed space that might need to be entered for work purposes.

 

[DandyDon]

Ok guys I will leave it at that, I was hoping to ask some constructive questions and learn something myself. If I passed on any info in the process it would be a bonus.

Minimum legal requirement when entering a confined space is to measure for the standard 4 gases. I would personally think the risks in air quality are worse when under water.

I think if you can measure CO and O2 accurately then you're probably doing better than most. FYI CO sensors are cross sensitive to VOC's so sometimes you may not be picking up CO you may be picking up something else but either way you are on the safe side of the fence.

Anyone interested can pm me, I will stop filling this forum with my useless info.

Cheers and and safe diving to all

You are very welcome to post your opinions here, but it is a discussion thread - so just be prepared to explain yourself.

 

[Hvr4fun]

Removed post.