Carbon Monoxide tank risks and protections .

[tamas970]

Okay, reformulating the question: does it respond to a 1-3ppm bump gas?

How much does a replacement sensor cost (if there is any)?

FWIW Nuvair told me NOT to use breath as it contains a lot of moisture which over time will destroy a very expensive sensor.

Instead I bought a regulator off of ebay for $15 and you can find the gas in propane sized bottles at around $72. Then again I prefer the word industrial, over trial sized. Unless continually traveling, it just needs to be tested before a trip.

 

[swamp diver]

Over here the replacement sensor for the De-Ox CO monitor is $US260 which is pricey but the manufacturer says they are good for 5 years. For the older Nuvair units (pre-2011) the sensor is $160.

While human breath has a relative humidity of 100%, blowing into the analyzer for minute or two is not going to damage the sensor unless you possibly get some saliva into the units with no 'gortex-like' membrane in front of the sensor. That would include the De-Ox unit and the Pocket CO. The Analox and Oxycheq units have a water resistant membrane in front of the sensor to prevent free water ingress.

These same sensors are used all the time for breath CO analysis in smoking cessation programs and other breath CO-related research projects.
http://www.breathcotest.com/microCO.asp

 

[tamas970]

That puts the Analox back to business in terms of cost-efficiency (replacement sensor ~150$).

Over here the replacement sensor for the De-Ox CO monitor is $US260 which is pricey but the manufacturer says they are good for 5 years. For the older Nuvair units (pre-2011) the sensor is $160.

While human breath has a relative humidity of 100%, blowing into the analyzer for minute or two is not going to damage the sensor unless you possibly get some saliva into the units with no 'gortex-like' membrane in front of the sensor. That would include the De-Ox unit and the Pocket CO. The Analox and Oxycheq units have a water resistant membrane in front of the sensor to prevent free water ingress.

These same sensors are used all the time for breath CO analysis in smoking cessation programs and other breath CO-related research projects.
Breath CO The MicroCO

 

[swamp diver]

That puts the Analox back to business in terms of cost-efficiency (replacement sensor ~150$).

If you can find a local Analox distributor (stockist as the Brits call them) who will do your annual calibration for a reasonable fee then you are off to the races. Now while Analox recommends an annual calibration I have tested some units at the two year mark which were still within spec reading 9 ppm when a 10 ppm calibration gas was applied. As long as you could find some known low ppm CO calibration gas to apply to the sensor once a year in order to check the accuracy then you may get away with a full calibration once every two years if still in spec.

While the sensor for the De-Ox unit is significantly more expensive remember you truly don't ever have to calibrate that unit according to the manufacturer because the sensor has a calibration reference gas within which is why that sensor is so expensive and power hungry.

 

[tamas970]

This might also be limiting for the sensor's lifetime...
As long as the sensor works (reacts to 1ppm bump) I am not much worried about calibration. I can live with 1ppm/year drift for 3-4 years (knowing that I have to reduce my tolerance from 5-6 to 2-3ppm)

While the sensor for the De-Ox unit is significantly more expensive remember you truly don't ever have to calibrate that unit according to the manufacturer because the sensor has a calibration reference gas within which is why that sensor is so expensive and power hungry.

 

[swamp diver]

This might also be limiting for the sensor's lifetime...
As long as the sensor works (reacts to 1ppm bump) I am not much worried about calibration. I can live with 1ppm/year drift for 3-4 years (knowing that I have to reduce my tolerance from 5-6 to 2-3ppm)

We don't know how the new De-Ox self-calibrating CO sensors are going to perform over the expected life span of five years.

You will still want to bump check whatever unit you get using a known 10 ppm CO gas each year to make sure the sensor is not at the end of its life. You could bump check it routinely with a 2 ppm breath test but when 10 ppm test gas is applied it may still read 2 ppm at which point it will need a full calibration or a new sensor if the analyzer will not calibrate using the specified span gas concentration.

 

[robbcayman]

I'm thinking about buying the newer analox. I will only use it a few times a year, but the peace of mind knowing my tanks are safe should be worth it. Did Cozumel ever get analyzers on their setup's, Don? I know you pushed them toward it, but I never heard what happened.

 

[DandyDon]

I'm thinking about buying the newer analox. I will only use it a few times a year, but the peace of mind knowing my tanks are safe should be worth it. Did Cozumel ever get analyzers on their setup's, Don? I know you pushed them toward it, but I never heard what happened.

There were some inline monitors bought in a partnership for the biggest compressor operation there, but installed with less than preferred options - and some disappointments. The rest of the story is not worth trying to tell, IMO. DAN & Analox then partnered to give some monitors to some Ops on the island and on the peninsula, but I don't know which ones - much less how they were installed and have been operated. I didn't think much of the DAN action, throwing some money at a few Ops when there is a whole world of unknown compressors - would have rather seen the money used for publicity about the need and education about solutions.

It doesn't matter to me where the tanks supposedly come from or what equipment the compressor supposedly uses. A few Ops do have portable testers altho not nearly as common as Nitrox analyzers, and who knows how & when they were calibrated. I test all my tanks, and I have my analyzer calibrated by Analox ever year. Last year all they had to do was replace the battery, but whatever it needs - their call.

Before the development of the portable Analox CO unit when I was still using the Pocket CO, I tried to tell a manager in Roatan about the 5ppm readings I was getting, but he just argued that it couldn't happen.

I don't trust anyone anywhere, thank you. I admire my home LDS in Lubbock for their quality & attitude, but when I pick up a tank filled by them - I test it then and there. They don't seem to have anything to hide nor mind in the least.

 

[N2Purge]

Having been on a liveaboard where half the divers got sick, I have seen CO poisoning first hand and it is a serious problem that could easily kill someone. We had divers puking, and many others with severe headaches. That is way to close to the edge for comfort. Fortunately no one died, the boat owner rebuilt his compressors, and added CO analyzers.

At this point it is time to start hounding the local dive shops to upgrade their compressor systems with a continuous CO monitoring system. Not just their air tests done right after a filter change, and service. The costs are not expensive and it could save lives.

As I understand it some of the paramedics have started carrying CO analyzers on their persons so when they enter a home or business they are protected from a gas they can't see or smell, and in NY at one residence their alarms were screaming at them.

It may also be the diesel boats...
Diesel particles pose heart risks | Archive news |