Is it possible to make a homemade hygrometer?

Question

If not, what is the cheapest price?

I need one that measures the humidity in the air. They look pretty expensive, so I am wondering if I can make one myself.

Answer 1

Depending on how fancy or accurate you wish to get, there are a few options for you.

You can actually use hair to make a hygrometer, as shown here: http://www.essortment.com/hobbies/homema...

A more accurate method, although pricier is to use a wet and dry bulb thermometer and a psychrometric chart.

Wikipedia.org has a great article on hygrometers that may help you decide which option works best for you.