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.

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quickthrowman an hour ago | parent [-]

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

	▲	colechristensen an hour ago \| parent [-]
		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.