[time-nuts] Temp/Humidity control systems?

[Ron Bean]

>* You cannot "feel" absolute humidity, always measure it.

And since this is time-nuts: Measuring humidity accurately is tricky. 
According to people who have tested them, commercial electronic humidity 
sensors, when tested in a lab, have never come anywhere close to the 
accuracy claimed in the data sheet. The best you can hope for is 
consistent readings, not absolute accuracy.

The exception is the "cold mirror" type of sensor, which measures the 
dewpoint by cooling a mirror and bouncing a light off it to sense the 
temperature where dew condenses on it. Those are expensive, and they 
require maintenance to keep the mirror clean.

BTW some of us are more sensitive to humidity than others. I can't tell 
you the RH of a room, but I can tell you when it's too dry for comfort. 
I want it as close to 50% as I can get it without growing mold on the 
walls. Some "experts" claim that 30% is good enough for anyone, but 
they're wrong.