[josephg]

Should…

Whenever I travel, I bring a CO2 meter with me. It’s amazing how often the air is bad. Often in unexpected places. My meter hit 3100 in an uber once. I didn’t even notice until I got to my hotel room and looked at the data log. It was a fresh, hot day outside. The uber had windows closed and AC on. I bet he had no idea - but he was driving with significant cognitive impairment. Takeoff and landing in planes are always the worst. If you get sleepy as the plane is taking off, it’s not you. The plane’s ventilation doesn’t work properly when the plane is stationary. So before a plane is in the air, they often hit 2500.

[sarchertech]

He’s not driving with significant cognitive impairment. Submarines and the ISS routinely operate at 5000 ppm. 60 years of studies and almost a century of operating submarines has shown no impairment at 5000 ppm.

Then all of the sudden Satish 2012 comes along and shows serious cognitive impairment at 1000 ppm. The only studies that have replicated this involved Satish. Studies without Satish as a coauthor fail to replicate their findings.

If you think about it for a second, the levels of impairment Satish shows don’t make sense at all. You’d expect to see differences on SAT scores of hundreds of points between test centers with good ventilation and bad. You’d expect to see massive differences between regions where AC is more or less common. Or even between seasons.

[jerlam]

Cars have a "make the air bad" button, the recirculation button. Some people always have it on. I wonder if it's a factor in road rage.

[fingerlocks]

Sounds like you need to change your cabin filter.

[dnemmers]

I think the 'make bad air' part, is that it allows carbon dioxide levels to build up...not that the air is unpleasant to the senses to breathe.

[josephg]

Perhaps a lot of people should change their cabin filters.

Air quality should be good everywhere. But its not. You can't tell if you don't measure it.

[hansvm]

Interesting. I can barely stay awake in typical commercial planes, and I always attributed it to the lower partial oxygen pressure.

[quickthrowman]

When was the last time you had that sensor calibrated properly with a can of test gas and a multimeter?

[colechristensen]

Take it outside, as long as it measures 400-450 it's probably good.

Metrology calibration is necessary if you want accuracy better than 10%, but most of us don't care at all about that, instead we care about increments of 200ppm or more.

[jameshart]

Haha yes. 400-450ppm is fine. We’re doing just fine here. Everything is okay.

https://www.co2levels.org/

[jaapz]

The comment was about the accuracy of the sensor, not about raising CO2 levels across the globe.

[jameshart]

Sure. It just draws attention to the fact that a throwaway piece of advice for checking calibration of a CO2 sensor is ‘it should read 400-450ppm outside’ when a few short decades ago that advice would have been ‘it should read 300-350ppm outside’.

It’s like if someone said ‘you can check if your chatbot’s news feed is complete and up to date by asking it for ‘recent mass shootings’. There should be two or three in the past seven days’. It’s true and a valid methodology but holy crap does it say something dark about where we are.

[ShinyLeftPad]

Local factors can make your CO2 fluctuate by 200ppm. If you're near a busy road with not a lot of wind 600 ppm is possible. But it's not that important if you open your window at 1000 ppm or 1200 ppm.