How to Make a Hygrometer
Things You'll Need:
- 9 inch by 4 inch piece of wood or strong Styrofoam
- 1 piece of thin, flat plastic, at least 3 inches by 2 inches
- 3 8 inch long human hairs
- 2 nails
- Sturdy scissors (for cutting the plastic)
1.Cut the plastic into a triangle 3 inches tall and 2 inches wide.
2.Tape the dime onto the piece of plastic near the tip of the triangle.
3.Pierce one of the nails through the triangle along the 2-inch side for the pointer. Turn the pointer until it moves freely around the nail.
4.Glue one end of all three strands of hair to the pointer between the nail and the dime. You need to use human hair since it curls when the air is moist.
5.Hammer the nail through the pointer to the wood or Styrofoam base, about 6 inches from the top.
6. Directly above the nail that is through one end of the pointer, hammer the other nail into the wood 1 inch from the top of the board.
7. Glue the free ends of the strands of hair to the top nail so that the hair strands are straight and taut and the tip pointer is parallel to the ground.
8. Place the hygrometer in a spot where you want to measure the moisture in the air. If it's humid, the hair will expand and the pointer will point down, if the air is drying out, the pointer will point up.