Carbon monoxide discussion - split from Fiona Sharp death in Bonaire thread

[Dan]

@DandyDon thanks for the tip about calibrating the CO detector with my own breath. My breath is emitting 5ppm CO! Is that good or bad?

 

[DandyDon]

You are right about that. What CO concentration do you measure from your breath? I'm guessing about 1-5 ppm?

Yeah, generally, if your CO tester is accurate.

DandyDon thanks for the tip about calibrating the CO detector with my own breath. My breath is emitting 5ppm CO! Is that good or bad?

A little high for a non-smoker, or do you? Maybe your unit hasn't been calibrated lately. My Sensorcon hasn't, so it won't be accurate, but close enough to deal with big risks. I did not say for calibrating tho, just testing for ballpark reactions.

Actually, we breathe out a little CO, enough to test a CO tank tester

Edited by chillyinCanada cuz oops I forgot this is A&I thread

Some countries limit tank CO to 3ppm, some 5, the US 10 - while most have no rules. An accurate 5ppm taken to 130 feet would be similar to 25ppm in effect. It's more complicated than that, but not life threatening if accurate. It's just difficult to measure accurately in parts per million tho. I'm guessing it's the pressure of blowing into it temporarily threw it off, and then there is humidity. I can get mine into triple digits blowing hard. This is why the tube connected to air flow didn't work.

 

[KenGordon]

Yeah, generally, if your CO tester is accurate.


A little high for a non-smoker, or do you? Maybe your unit hasn't been calibrated lately. My Sensorcon hasn't, so it won't be accurate, but close enough to deal with big risks. I did not say for calibrating tho, just testing for ballpark reactions.



Some countries limit tank CO to 3ppm, some 5, the US 10 - while most have no rules. An accurate 5ppm taken to 130 feet would be similar to 25ppm in effect. It's more complicated than that, but not life threatening if accurate. It's just difficult to measure accurately in parts per million tho. I'm guessing it's the pressure of blowing into it temporarily threw it off, and then there is humidity. I can get mine into triple digits blowing hard. This is why the tube connected to air flow didn't work.

Are you feeling ok? https://www.atsjournals.org/doi/full/10.1164/ajrccm.158.1.9711066

I wonder what happens to exhaled CO in a breathing loop. Can you get someone, ideally a smoker, with a rebreather to spend half an hour on the loop on the same dil and then test it for CO?

Meanwhile, I am not sure I trust your CO meters.

 

[DandyDon]

Are you feeling ok? https://www.atsjournals.org/doi/full/10.1164/ajrccm.158.1.9711066

Yeah, most of my three digit reading was from blowing hard. The Sensorcon CO Inspector doesn't deal with flow rate well. An Analox restictor can make it behave, but I didn't retrieve one.

Meanwhile, I am not sure I trust your CO meters.

I have a couple of better units. The Sensorcon is what he illustrated earlier, and it is the lowest cost protection in tank testing - not so accurate depending on circumstances, but adequate used in a zip lock to avoid serious injury or death.

I wonder what happens to exhaled CO in a breathing loop. Can you get someone, ideally a smoker, with a rebreather to spend half an hour on the loop on the same dil and then test it for CO?

I have no idea, but I seriously doubt that anyone would produce enough to matter.

I am always game for keeping a CO discussion in the right direction within my abilities, but I doubt that it had anything to do with this fatality. There was no information given to support that statement, and I really suspect it was just sloppy journalism. I doubt that people who enjoyed high school chemistry and are nit-picky by nature are common in news writing.

 

[The Chairman]

Actually, we breathe out a little CO, enough to test a CO tank tester. I guess you don't have one? Someday we may discover a benefit to very small amounts.

Mostly smokers do this. Non smokers? Not so much. I have never been able to get a reading on my CO meter.

 

[DandyDon]

Mostly smokers do this. Non smokers? Not so much. I have never been able to get a reading on my CO meter.

Smokers more, yeah - but you should get a digit or two. Maybe it needs testing or calibrating. CO sensors all drift a lot.

 

[Dan]

A little high for a non-smoker, or do you? Maybe your unit hasn't been calibrated lately. My Sensorcon hasn't, so it won't be accurate, but close enough to deal with big risks. I did not say for calibrating tho, just testing for ballpark reactions.

I’m not a smoker. I had to blow as hard as I could to the white-tip tube end to get that reading. I figure that it has a vent & filter to reduce the volume rate & moisture.

If I just exhale right on the sensor, it stays zero.

 

[Dan]

Mostly smokers do this. Non smokers? Not so much. I have never been able to get a reading on my CO meter.

Blow harder to the tube for 5 seconds and tell us what you read.

 

[rsingler]

I think a reading from blowing hard may not be a reading, but an artifact. I see the same thing when calibrating nitrox with my O2 meter. If I pressurize the sensor, the oxygen percentage goes up. If I crack the valve too hard, and seal the lip of the sensor up tight to the DIN valve, I get erroneously high readings.
Maybe one of our engineers can tell us if that's a valid observation, and if so, why that happens.

 

[tursiops]

I think a reading from blowing hard may not be a reading, but an artifact. I see the same thing when calibrating nitrox with my O2 meter. If I pressurize the sensor, the oxygen percentage goes up. If I crack the valve too hard, and seal the lip of the sensor up tight to the DIN valve, I get erroneously high readings.
Maybe one of our engineers can tell us if that's a valid observation, and if so, why that happens.

The measurement is from certain size molecules getting through a special membrane. More pressure, then more wrong molecules getting pushed through.