Is there a natural way to read the amount of humidity in the air?

Question

Is there a natural way to read the amount of humidity in the air?

Answer 1

A psychrometer measures compared evaporation rates of wet versus dry media by weight  This is a measure of relative humidity

Answer 2

The easiest thing you can do is measure "wet bulb temperature." I'm sure you'll do this experiment in school eventually, but it works like this:

Get 2 thermometers. Set one in the shade to measure the actual temperature. Attach the other to a string using tape or something. Then get a wet paper towel and tie it to the end (the "bulb) of the thermometer. Now, spin the thermometer around on the string for a few minutes.

The evaporating water from the paper towel will cause the temperature read by the thermometer to decrease. Since lower relative humidities allow for more water to evaporate, the greater the difference between the dry and wet bulb thermometers, the lower the relative humidity.

If you want to get specific, you can use a psychrometic chart (http://en.wikipedia.org/wiki/Psychrometr... ) to look up the exact value for relative humidity. The one on wikipedia has the wet bulb temperature along the top in blue, the dry bulb temperature along the bottom in green, and relative humidities curving through the graph in red.

Answer 3

Fill an empty bottle with water and freeze it. Remove it from the freezer and dry the outside of it. Stand it in a clean dry tray. Humid air in contact with the bottle will condense on it's surface and run into the tray. Collect this water and measure it's volume. If the whole apparatus is in a sealed unit and you know the volume of air in there you can calculate the relative humidity.

Answer 4

If you have a length of curly hair hung on a weight, you could in theory detect humidity changes by the changes in length of this hair.