Question on Carbon Monoxide

[roastbeef]

Run your air intake away from your compressors engine exhaust and make sure your filter catridge contains a catylist for carbon monoxide (C0) removal. The more babling you read on these discussion boards the more confused you'l get so just follow the manufactuers recommendation and you will be fine.

 

[Hickdive]

Here you go:

http://www.bauer.uk.com/Bauer/Shooting/products/Spares/P%20Filter%20System%20Cartridges.pdf

I have a PE100 Electric and use a P21 Part No.057679

Since you have the petrol model you need a P21 Part No.059183 which contains a CO converter (hopcalite). The hopcalite takes up some room in the cartridge so you have less space in the same size part for activated carbon hence you get a slightly lower processing capacity (110Nm3 as opposed to 130Nm3).

As may be seen, your reading of 1ppm is within the limits of the cartridge (5ppm) and well within the limits of DIN EN12021 (15ppm).

Don't forget that hopcalite is a catalyst that converts CO into CO2 and that it gives up that CO2 when under pressure. So you need purge the filter for a couple of minutes after starting and getting up to operating pressure otherwise you'll pump any CO2 released into your cylinder.

If you need a compressor repaired or serviced then I can recommend Colin Bruce. PM me if you want his number.

 

[captain]

No testing data but having run a gas powered compressor for going on 40 years I have never experienced any type of air purity issues using carbon and sieve and good compressor operating pratices.

 

[NAM001]

Phil..... I too use a gas powered compressor . A RIX-6 ,,,I follow up the compressor with a hyperfilter stack whick has co-co2 conversion in it. Although i have never had it tested in the past 5 years i can say i have not noticed any physical abnormalities. On my input i have the snorkle tube up wind and about 6' above the compressor also a backpresure reg on the filter output to maximise the effectiveness of the filter. I cant comment on the accuracy of your meter but you could have a sample taken and analyzed so you know just what 0-1 ppm your meter means per lab testing. Also as far as back presure regs go i have one on the output of the moisture seprerator (to max the moisture removed) and one on the output of the hyperfilter (to max the filtering ) in the fill whip. the one on the output of your factory p0 covers the moisture seperator part of it. If you decode to go the hyperfilter route, you may want to think about that.

There is a document about how compressors and filter work. Great read and makes simple the use of filters, back presure, moisture and the like. PM me and i will se if i can find it if you want it.

 

[DandyDon]

I'm late to this discussion, but you can ignore comments from anyone who claims no problems - but does not test for CO.

Your Analox portable CO analyzer needs to be dial calibrated in clean air so that your zero setting is dependable, but thereafter - finding a 1 ppm is nothing to worry about. Some countries do allow for 10 & 15 ppm maxes, most don't have regulations, but I'd suggest 3 ppm is time for concern, 5 ppm is time for refusing the tank.

Phil, relax and go diving. your levels are fine. make sure you keep your analox calibrated, filter fresh, change your oil as required by Bauer, and make sure your intake is up wind. If you use a long intake hose make sure the hose has an over sized diameter. Bauer recommends 1\4 in oversize for every 10 feet.
Canada's max CO level is 5ppm. USA is 10ppm. I am not sure on the UK.
ZDD

UK is 3 ppm.

 

[mala]

keep the exhaust downwind of the air intake.

 

[Doc Harry]

Normal air contains about 1 ppm CO

A normal person's exhaled breath contains about 3-4 ppm CO

A smoker's exhaled breath contains about 7-9 ppm CO

 

[IyaDiver]

Typical Honda gasoline engine pumps out approx 300 PPM from 1 meter of its exhaust tip.
Open air filling but with walls on one side ( 180 degrees ) is still a risk.
The best is totally open air filling with no walls or buildings and get the wind-to-compressor orientation right.
Bauer

059183 has very little hopcalite but at the least there is some.

Yes, lousy compressor oil will produce CO too when compressor get hot.

15 PPM CO wont kill you even at 40 meters but it does shows something is wrong either with the compressor or how we operate them.

Safe pumping........​

 

[spoolin01]

I gather that you recognize this already, and others have alluded to the same, but if you're concerned about either the 1ppm CO itself or what it says about your compressor setup, it would probably be best to first independently confirm the reading. The Analox has a stated range of 1-50ppm with good accuracy, but as a general rule for analytical instrumentation, reading at the lower limit of detection shouldn't be taken accurate for granted, without regular and specific verification of the unit in question. Dandy Don seems to know these well, maybe he has knowledge of what Analox or users have done to back a claim of a 1ppm quantitative limit.

 

[DandyDon]

I gather that you recognize this already, and others have alluded to the same, but if you're concerned about either the 1ppm CO itself or what it says about your compressor setup, it would probably be best to first independently confirm the reading. The Analox has a stated range of 1-50ppm with good accuracy, but as a general rule for analytical instrumentation, reading at the lower limit of detection shouldn't be taken accurate for granted, without regular and specific verification of the unit in question. Dandy Don seems to know these well, maybe he has knowledge of what Analox or users have done to back a claim of a 1ppm quantitative limit.

I may not be clear on the question, but I'll explain my approach...

1: When my Analox portable CO analyzer was a year old, before my next trip, I sent it in to be checked. They don't think it's necessary to calibrate since it has the field calibration, but as new as much of this is - I wanted it tested. It passed without any needs.

2: For the field calibration, I prefer to be on the water and not moving, as urban areas can have elevated ambient CO and a moving boat can have a stationwagon-effect of exhaust - but in the real world, I'll do the best I can.

3: I'd ignore a 1 ppm as negligible and possible just rounding or my jiggling of the unit. 2 or 3 ppm gets my attention, and I have dived 5 to 7 ppm - but won't now. What if my field-cal was in 5 ppm ambient air and the unit is giving me 5 to 7, which is really above my field-cal setting?

4: I am also calibrating my Pocket CO unit before my next trip and taking it & bags for backup testing.

5: And of course, I'd invite the Operator to test while I watch if he has a unit. I would be surprised it he did, and still wonder if it was calibrated, but we could compare. If he hasn't got one, screw it - mine wins.

The good news is that with more and more divers field testing, the Ops seem to be trying to protect their business and us by supplying cleaner air.