We have Hygrometers in 3 sizes – 1-7/16, 2-3/4 and 3-1/2 inches. Plenty of variety
for everyone. Hygrometers are the most misunderstood of the weather instruments. They give
the relative humidity, among of water in the air as a percentage.
For example, if it 20% humidity you are probably in Arizona or New Mexico. If it 98% humidity you may
be in Houston. If it’s summer in Houston and 50% humidity inside your home, then you have
a really good air conditioner system.
Instead of a bi-metallic coil as seen in a thermometer, hygrometers use a metal coil
coated with a chemically impregnated paper. Any changes in the humidity, or water vapor
in the air, cause the coil to bend, resulting in the movement of the indicator hand.
Never ever touch the coil with your fingers !
Like our thermometers, one end of the coil is attached to the case and the other is attached
to the shaft that holds the indicator hand. The bending coil causes the indicator hand
to move as the humidity changes.
It’s surprising how important humidity can be. Hygrometers are used in saunas, greenhouses,
museums and factories that apply paint and various coatings. Proper care of wood musical
instruments requires the use of a hygrometer as well. In your home low humidity increases
static electricity and dry skin. High humidity can encourage mold growth.
It’s not a bad idea to have Hygrometers around you. In the late 1700’s, the first
hygrometers were made using human hair, about 10” long, under tension. These early hygrometers
were made even more accurate by using ether to remove some of the oils found in human
hair. Whale bone was also used for hygrometers. They have been around for a long time.
Our hygrometers actually measure the absence of water. To do this properly initially the
hygrometer needs to be “charged”. You can do this by quickly folding
a very warm, moist towel and placing the back side of the hygrometer on it.
Within a few minutes the reading on your hygrometer should be about 95%. If it’s not, then use
the setting screw on the back to adjust the indicator hand to about 95%. Your hygrometer
is now set for several years of good operation.
A popular use for hygrometers is cigar humidors. In the 1990’s these were so popular that
all worldwide production could not keep up with the demand. I would be virtually impossible
to find a good humidor that did not have a hygrometer in it.
For all of the men ( and women) who occasionally who smoke a cigar, a humidor is a popular
item. It’s also a popular item for woodworkers to make. When you do decide to smoke a cigar
it’s nice that it’s not too dry or wet. Just right if you are so inclined.
We are clockparts.com, and I’m Mike Brosman. I hope you have learned about the value of
a hygrometer or two around the house.