Just for the fun of it, here is how NIST measures humidity. https://www.nist.gov/sites/default/files/documents/calibrations/sp250-83.pdf
On Thu, Oct 27, 2016 at 3:30 PM, William H. Fite <omni...@gmail.com> wrote: > NIST-traceable hygrometers are readily available in the $200-$400 range. > > Or you can get a couple of airtight boxes of precisely the same volume and > go gravimetric....................... > > On Thu, Oct 27, 2016 at 9:43 AM, Ron Bean <t...@rbean.users.panix.com> > wrote: > >> >* 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. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> > > > > -- > Intelligence has never been proof against stupidity. > -- Intelligence has never been proof against stupidity. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.