Gideon wrote:
wrote in message
. com...
You don't need a hygrometer, just a thermometer and a cotton ball.
Cover the thermometer's bulb with the cotton and dip it in water.
Shake the thermometer to help the water evaporate, and after a minute
of this the temperature should stabilize. This is the wet bulb
temperature. Compare it to the normal room temperature, which is the
dry bulb temperature, and look up the readings in a psychometric chart
to find the relative humidity. These charts are available from several
Internet sites or in about any book about air conditioning, including
factory auto repair manuals.
Yeah, that sounds a lot easier and more efficient than buying a
$5 hygrometer. I'll get on that soon, but right now I'm out in the
garage manufacturing some new brake rotors out of scrap iron.
I figure I'll save 5 or 6 dollars per axle and only waste a couple
of hundred hours of my time.
I didn't know hygrometers were available for as little as $5, but I
haven't shopped for one in a long time. On the other hand the method I
described takes only a few minutes and saves a trip to the store,
although I use the humidistat built into my tachometer.