Q&A for How to Make a Hygrometer

You can use your own. Horse hair is not essential for this project, as your hair and horse hair both absorb humidity.

The width and length are nine inches and four inches, respectively. If you are using longer or shorter materials, this will vary depending on the size change.

Sure, as long as you clean it. You should rub it with rubbing alcohol, and then rinse it with shampoo.

One is wet and one is dry. If they are the same, then there's no point of using two thermometers.

You would be better off using shampoo and conditioner.

Use as much as needed for the back and the front to hold the thermometers and gauze in properly. You can also make an additional triangle of cardboard attached to the back of the larger piece so it can stand up on its own.

It needs to be at least 12 inches long. If it is longer, cut the leftovers with a scissor.

Yes, horse hair absorbs humidity as well as human hair. Just be sure to wash it first.

You can use either, because the gauze is basically made out of cotton. I tried it and it works the same.

No you can't because the hair expands cause of humidity. If you used thread or yarn, it just wouldn't work.