sense / nonsense of CO monitoring

[tbone1004]

I meant in regular, uncompressed, unfiltered natural air. It seems to be backed up as a common value in populated areas by the local governments environmental department

correct, there is always some CO in ambient air, with the specific value dependent on a myriad of factors. That said, because of the dangers of CO at higher partial pressures, we have to be VERY careful which is why we try to filter it all out. Oiled compressors will also generate CO by nature, so what comes into the intake doesn't matter so much since the compressor will increase the CO concentration to dangerous levels and must be taken out.

 

[Wookie]

I meant in regular, uncompressed, unfiltered natural air. It seems to be backed up as a common value in populated areas by the local governments environmental department

I thought your numbers looked quite high, so here is the monitoring data for Florida for 2018, published in 2019. This is both grab samples and a TWA for the spots that have real time monitoring. Maybe Florida has less CO than the rest of the world?

https://floridadep.gov/sites/default/files/2018-CO-Design-Values_0.pdf

 

[wstorms]

I thought your numbers looked quite high, so here is the monitoring data for Florida for 2018, published in 2019. This is both grab samples and a TWA for the spots that have real time monitoring. Maybe Florida has less CO than the rest of the world?

https://floridadep.gov/sites/default/files/2018-CO-Design-Values_0.pdf

Thanks for sharing. It made me dive a little deeper into the report I read; turns out I was wrong in reporting it as absolute measurements. The study focused on air quality and used <10 ppm as a measurement bracket in their dataset, not as absolute figures.
So although the exact natural concentration does vary a little bit around the world, it is definitely lower than 10ppm

 

[Miyaru]

I had CO-Clear analyzers on my air compressors, with a range of 0-10 PPM and an accuracy of + 1 PPM. They usually ran at about 0.1 to 0.2 ppm, and the alarm was set to 0.5 PPM. I never had an alarm. You use the hopcalite in the filter to make the CO zero and the CO monitor to warn you if the hopcalite goes south, IMO.

That's what I've done now, installed a separate filterhousing after the compressor with hopcalite.
What's the amount of required hopcalite and dwell-time? I've only found this as a guideline: 1 gram per 5 liters/minute flow.

 

[KDAD]

@wstorms interpreting the chart posted by @Wookie the 2nd highest CO concentration measured in air that the public breaths in the entire state of Florida in the whole year of 2018 in the was 1.7ppm. This is from State and industry run monitors that are very accurate and operate continuously 24/7 365 days.

My day job involves the measurement of air quality and the highest CO concentration we have measured from continuous monitoring in the air immediately outside of petrochemical refineries over the past 10 years is less than 3.0 ppm.

For reference, the accuracy of the monitors that we use usually have an error of less than 0.3 ppm over the entire range of 0 to 50 ppm.

 

[wstorms]

@wstorms interpreting the chart posted by @Wookie the 2nd highest CO concentration measured in air that the public breaths in the entire state of Florida in the whole year of 2018 in the was 1.7ppm. This is from State and industry run monitors that are very accurate and operate continuously 24/7 365 days.

My day job involves the measurement of air quality and the highest CO concentration we have measured from continuous monitoring in the air immediately outside of petrochemical refineries over the past 10 years is less than 3.0 ppm.

For reference, the accuracy of the monitors that we use usually have an error of less than 0.3 ppm over the entire range of 0 to 50 ppm.

yup, I made a mistake with the normal concentration.
But for me the ambient value doesn't really matter that much, since any reading other than 0 is a "no go" as far as I am concerned. So now, I am looking for a sensor that has accuracy like the one you mention, is affordable, is easy to read out and can be sourced locally (The Netherlands). If you do have any suggestions, I am all ears

 

[UTscuba]

an additional problem with non-zero CO is that CO poisoning is cumulative, because CO irreversibly binds to hemoglobin and prevents it from carrying O2 around your blood. And the more CO you inhale, the more hemoglobin you lose. Hemoglobin molecules last for around 90 days in your bloodstream before they get replaced, so it takes around that long for CO poisoning to clear from your system.

 

[grf88]

an additional problem with non-zero CO is that CO poisoning is cumulative, because CO irreversibly binds to hemoglobin and prevents it from carrying O2 around your blood. And the more CO you inhale, the more hemoglobin you lose. Hemoglobin molecules last for around 90 days in your bloodstream before they get replaced, so it takes around that long for CO poisoning to clear from your system.

Do you have a source for that. Since we exhale a tiny fraction of CO with each breath it suggests that it is not irreversibly bound.

 

[kelemvor]

Obviously it's not completely irreversible otherwise we'd all be dead after a few months or years of living in a world with combustion engines. I'm sure it's really a case of your body eliminating CO is a very slow process.

 

[Wookie]

Do you have a source for that. Since we exhale a tiny fraction of CO with each breath it suggests that it is not irreversibly bound.

Ummm. We exhale CO2. Cars exhale CO.