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SurfLung
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Good To Know...

Thu Sep 28, 2023 3:32 pm

Good To Know...
- We talk alot about the quality of air that our compressors are capable of. I know my Alkin W31 Mariner has a spec that claims it purifies air to meet the "EN 12021" standard for quality. There's another standard called "CGA Grade E". I know we can have our compressor air analyzed to confirm it's level of purity. But what specifically do these standards mean?
- Recently I was on the MAKO compressor web site and they actually had a chart that defines the air quality standards.
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Personal Experience with Carbon Monoxide (CO)
- I have an electronic CO detector in my garage because I fill tanks there during the Summer months. This is with my electric powered RIX and Alkin compressors. I was wondering if the CO detector was working because it never seems to detect any CO.
- But then last Summer, I wanted to use my little gas powered Coltri MCH-6 compressor. I usually set this up outside and with a 10 ft air intake hose positioned high and up wind of the gas engine exhaust. Unfortunately there was not much of a wind to blow the exhaust away. There WAS some wind but it was kind of mild and on and off... I figured it was enough. I started filling my Twin 38s and everything was going nicely. Then, I took my electronic CO detector and placed it right next to the air intake. The next time I looked at the detector, it was reading 38 ppm of CO! What the heck? So I moved the detector around a bit trying to locate a position where it was free of CO... It changed to 68 ppm CO. CRIPES!
- Then I started thinking, "How much CO is acceptable?" Well... NONE! So I turned off the gas engine and emptied out the tanks. The chart above indicates that a certain amount of CO is acceptable in both air purity standards. That's interesting...

Conclusions of using my gas powered compressor...
1. Only use it when there is a definite wind blowing in a consistent direction... So that the intake can be positioned upwind of the exhaust.
2. Use my electronic CO detector to confirm no Carbon Monoxide at the intake.

PS. My CO detector is a household unit that has battery backup... I can plug it into the wall or use it portably.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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rhwestfall
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Re: Good To Know...

Sat Sep 30, 2023 5:57 am

I don't have it handy, but there is also a Canadian standard for air for scuba. It has a very low water standard (specifically for very cold water diving) and, IIRC, lower CO.

I don't think those standards are the actual ones. The ones I've seen quantify water, and list a few more things..
Bob

No Longer Awaiting my Kraken.....

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Drado
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Re: Good To Know...

Sun Oct 01, 2023 5:31 am

Aside from CO monitors, are there currently any other gadgets and gizmos that can be used to check the quality of the air in tanks without the need for sending it out to a lab?
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luis
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Re: Good To Know...

Sun Oct 01, 2023 10:06 pm

Drado wrote:
Sun Oct 01, 2023 5:31 am
Aside from CO monitors, are there currently any other gadgets and gizmos that can be used to check the quality of the air in tanks without the need for sending it out to a lab?
Hi Ed,

There are some field test devices that I have seen used like on Navy vessels to check for the compressed air for SCBA (fire fighting), but I have not seen it used anywhere else. They ran the air through some glass sampling tubes (one time use only), but I am not even sure what all they were testing for. There is a different glass tube for every test. Moisture was one of them for sure and I am sure VOC (volatile organic compounds) and CO are some of the others, but this was not in my direct swim lane at work.

The DC (damage control) portable compressor on Navy vessels are really nice Bauer units with Yanmar Diesel engines. They are really nice, but anything with a diesel (and you may be fighting a shipboard fire) is going to be a concern the quality of the surrounding air you are pumping into your 4500 psi SCBA cylinders.


The good news is that for most diving situations using rental cylinders, the only really deadly contaminant that I am concern about (for this short exposure) is CO. So having a means of testing for CO is (IMHO) a very good tool. I am very happy with the method that I am using. I only do a sampling, but I started testing recently.
Luis

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Drado
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Re: Good To Know...

Tue Oct 03, 2023 9:39 am

Do CO monitors expire (like O2 meters)? Is that something that we should bring around for added peace of mind?
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SurfLung
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Re: Good To Know...

Mon Oct 09, 2023 9:57 am

This is an inexpensive CO detector I bought a couple of them for $4.95 from a pilot store. It last about 12 months after you open it. I'm going to use it along with the 6 spot moisture card in that simple test chamber described in the Alkin filter post.
Image
https://www.mypilotstore.com/MyPilotSto ... b63fa74ad0
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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