My Portable CO Monitor/Tester Field Experiences .

[DandyDon]

I fill my Tanks at my local Vol Fire Dept of which I am a member of.
We have a really great system with a CO monitor set at 0ppm.
You should join your towns FD, I am sure they are a great bunch of folks.

Haha, I fought many a grass fire along with them in my younger days. I think I'd get in the way now, but I will be talking with them about CO hazards.

 

[swamp diver]

Yeah, I have learned a lot here, and more fully appreciate the limitations and false positives available with the Pocket model. On future trips, I expect I'll...

• Wear it face down on my shirt collar on the planes, as I understand many of them don't have any CO monitors - and I would like to know even if the $300,000 year pilot isn't bothering to check;
• Hanging from something in the hotel room - I have never noticed a CO monitor in one;
• In an airtight cigarette box until I get to the tanks to test, then quickly inside the over bag to fill with tank air - minimizing exposure to humidity and other vapors;
• Maybe hanging from my collar on boats, even tho that will expose it to humidity.

The CO Experts, even starting at 10 ppm might not give the lower readings we'd prefer, but would protect divers from the more serious threats of higher concentrations. Using one chart's listing of "100 PPM: Slight headache after 1-2 hours" at sea level, then I guess it would take around 20 ppm in a tank to cause the same problems at 130 ft - or around that - with increased exposures building up worse reactions? I think the Maldives tragedy involved much worse concentrations. I see that it also tops out at 70 ppm max reading, so while one would know for certain not to breathe the tank, it wouldn't read the more serious contaminations like they had in the Maldives. The Pocket CO monitor claims to read up to 500 ppm.

Still, since the CO Experts model will protect in the 10-70 ppm range, I'd say that it gets the job done well, and the Dimensions: 6"x3.75"x1.75" (HWD) - Weight: 10 ozs are not that much bigger than my Analox Nitrox analyzer. Better choice or second choice, depending on the traveling divers views on size, they both seem to be worthwhile products with important benefits. Someday soon I guess I need to take the best information from this thread in quotes and start a new one summarizing as not many who might find this thread today would read all the way thru it; they want to know what to do earlier I think.


I wonder if my local fire departments could help me with testing and calibrations? My home village is served by a volunteer department, but well equipped. They might have materials and training, or might be interested in expanding. Plainview with a population around 25,000 might be better equipped. My dive bud lives there and has had close calls at his shop and nice, modern home both with his Kidde alarms sounding, and knows of other close calls in the town. Lubbock fire department is probly keeping up to date, as I think I recall them loosing some department divers to CO poisoning years ago - unless my memory is wrong there.

I think your workarounds for minimizing the cross-sensitivities are very good ideas. You might pick up some aquarium charcoal or order up a bottle of activated charcoal below and put that in a mesh bag inside your air tight box. The charcoal will remove most of the volatile hydrocarbons, but not the NO and NO2 from traffic. I'd really try and keep the sensor protected from those contaminants and any alcohols (marker pens).
High pressure breathing air compressors, scuba air compressors, Scuba air

The humidity appears to increase the sensitivity of the unit such that a reading of 100 ppm will become 120 ppm at very high humidities. Not a big deal if a true reading as you are going to be very careful about diving with any amount of CO identified in the breathing air.

Your local fire department according to the new NFPA 1989 regulations which came out in March 2008 "shall" have an inline CO monitor on the fire hall's compressor (clause 7.2.1). In other words they should have a CO monitor on the compressor, and where there is a monitor there is calibration gas and regulator. Under the above standard the US fire services are limited to a maximum compressed air CO exposure of 5 ppm at 1 atmosphere since uptake of CO is greater while wearing a SCBA mask and during heavy exertion. If it is a small fire hall I am sure they might offer to help you out with calibrations. The gas cost for them to do a calibration is about $6 so I'm sure a case of beer might facilitate the matter.

 

[DandyDon]

I think your workarounds for minimizing the cross-sensitivities are very good ideas. You might pick up some aquarium charcoal or order up a bottle of activated charcoal below and put that in a mesh bag inside your air tight box. The charcoal will remove most of the volatile hydrocarbons, but not the NO and NO2 from traffic. I'd really try and keep the sensor protected from those contaminants and any alcohols (marker pens).
High pressure breathing air compressors, scuba air compressors, Scuba air

Yeah I keep meaning to get some activated carbon. Pocket CO does suggest that possibility in the manual.

The humidity appears to increase the sensitivity of the unit such that a reading of 100 ppm will become 120 ppm at very high humidities. Not a big deal if a true reading as you are going to be very careful with any amount of CO identified in the breathing air.

Oh ok, so the humidity is a minor problem. Still learning here, even after all the reading. Then I can wear it on a boat without ruining the days tests, just allow for higher readings maybe. Gotcha!

Your local fire department according to the new NFPA 1989 regulations which came out in March 2008 "shall" have an inline CO monitor on the fire hall's compressor (clause 7.2.1). In other words they should have a CO monitor on the compressor, and where there is a monitor there is calibration gas and regulator. Under the above standard the US fire services are limited to a maximum compressed air CO exposure of 5 ppm at 1 atmosphere since uptake of CO is greater while wearing a SCBA mask and during heavy exertion. If it is a small fire hall I am sure they might offer to help you out with calibrations. The gas cost for them to do a calibration is about $6 so I'm sure a case of beer might facilitate the matter.

My village department might have a compressor or might get them filled elsewhere. I'll be talk with them next week. Off to Santa Rosa NM tomorrow night for a SB gathering and dives. Steallas compressor is old, but electric and outside, but I'm testing of course - and showing the other divers.

 

[swamp diver]

I see that the company now has a scuba test kit out for an extra $50 for the bag and tank adapter.

There is a new tank mode which allows a 3 minute interval in the bag for sampling.

As long as there are no interfering vapours in the neighbourhood and the unit is freshly calibrated probably not a bad option for the traveling diver. Prolonged high humidity exposure while in the tropics may be an issue so best to store it in the air conditioned room at night.

Order the Pocket CO SCUBA - Carbon Monoxide Detector

 

[DandyDon]

I see that the company now has a scuba test kit out for an extra $50 for the bag and tank adapter.

There is a new tank mode which allows a 3 minute interval in the bag for sampling.

As long as there are no interfering vapours in the neighbourhood and the unit is freshly calibrated probably not a bad option for the traveling diver. Prolonged high humidity exposure while in the tropics may be an issue so best to store it in the air conditioned room at night.

Order the Pocket CO SCUBA - Carbon Monoxide Detector

Haha, they were going to send me an email on that. Oops. But then I had told them that I was pretty happy with my developed approach and hoped their ideas would not bump the price much, so the cost change might have caused me to be forgotten. Or maybe it was in my spam folder and I dumped it.

Not a bad looking kits at all with the bag, adapter, pelican box, calibration gas, test mode, and laminated card. I suppose one could still opt for the lower cost CO monitor only, add bad, pelican box, cal gas, and read from what we learned here - but I'd suggest that it looks like a nice package, worth the extra cost. And I like their "Facts About SCUBA diving and Carbon Monoxide" introduction. Sounds like they really did listen to us and other divers and do a good job of meeting the need.

Thanks Swamp Diver! I'll ring them Monday and ask about and add-on package for us who already have the 300 model.

 

[Bonuss]

Thanks Don,
I received my scuba version today from them. Looks good, haven’t even played with it yet. I went to a meeting in a large hall last week and several people were complaining of being dizzy. As a "building expert" I wanted to have it to carry in my car (stored). Now I have an excuse to plan a dive as well.

Bob

 

[partyper]

I have the scuba version, and I have tested it on a trip to the Read Sea. All tanks came up with 0 or 1 ppm, while walking from the boat to the bus in the harbour gave a reading of 12 ppm. The scuba version is quite easy to use, it can be a little tricky to fill the bag from a DIN valve, it would probably be easier from a YOKE valve, but otherwise no problems.

Regards

Per

 

[Pinepig]

Hey Don, I was just rummaging around SB and ran across this topic, CO2 is a problem in light aircraft as well ( I'm a CFI ) so I thought I'd dig around a little bit and see what our industry/sport had to offer for this, Take a peek at this,

Electronic Carbon Monoxide Meter - Sporty's Pilot Shop

Looks to be quite a bit smaller than the expert one you guys were talking about ( but bigger than the pocket one )

These are the folks that make it, and the page of that monitor.

Single Gas Monitor-Quest Technologies SafeTest 90 Personal Gas Monitors-Detector


I have not used one but it looked interesting.

Another thought, perhaps something cheap like this ( 10$ ),

Extended Life Carbon Monoxide Dectector - Sporty's Pilot Shop

for a trip might actually work, sealed in watertight cig case when not needed and to check gas, fill a baggie toss it in there and leave it for a min or two. I have used these in light aircraft and they do work but I have no idea what PPM they actually change color at.

I just found this too on AVweb about CO2 detectors, you'll like this,

http://www.aeromedix.com/aeromedix_articles/co/index.html

 

[swamp diver]

Another thought, perhaps something cheap like this ( 10$ ),

Extended Life Carbon Monoxide Dectector - Sporty's Pilot Shop

for a trip might actually work, sealed in watertight cig case when not needed and to check gas, fill a baggie toss it in there and leave it for a min or two. I have used these in light aircraft and they do work but I have no idea what PPM they actually change color at.

Last time I checked these discs change to a dark colour at 100 ppm of CO at which point an older, unfit diver will likely be in trouble if at 5 ATA. Accuracy is needed in the 0 to 10 ppm range.

If you read the aeromedix link you supplied under the section "Chemical Spot Detectors" these discs are not even recommended for pilot usage at 1 atm for multiple reasons.

 

[kgault]

Does any one have any experience with the "DE-OX SAFE Carbon Monoxide Analyser" by TEMC?
DE-OX SAFE carbon monoxide analyzer

It appears to work like an oxygen analyzer in that it can be used on tanks, or run continuously for sampling from a compressor. Info on the companies website is sparse, but some sellers (UK) indicate that it has a resolution of 1 ppm in the 0-300 ppm range.

I have not found any info on the life expectancy of the replaceable sensor.

Any Info would be appreciated.

Thanks,

Keith