You may not realize it but you are already wearing your very own hygrometer or humidity meter. It changes its appearance as the humidity level raises or drops and may even get frizzy in humid weather. You guessed it. It is your hair. Although you may not be able to determine the exact percentage of moisture in the air, you can tell when the humidity raises or drops. Human hair is exactly what you need to make your own humidity meter. Don't worry, you only need a couple of strands.
Cut a rectangle out of the plastic cover that measures 1 1/2 inches by three inches. Make a dot at the center of the1 1/2 inch side. Using a ruler, draw a line from the point to the upper right hand corner of the three inch side. Repeat the process drawing a line to the lower right hand corner. You should have an arrow shape traced on the plastic. Cut on the traced line to create a plastic arrow.
Place the arrow in front of you with the point facing to the right. Tape a dime to the arrow near the point.
Punch a hole with a nail near the base of the triangle. This should be centered between the angles of the triangle. Work the plastic back and forth over the hole. The arrow must move freely on the nail.
Glue one end of the three strands of hair at a point between the dime and the nail.
Attach a nail about one inch from the top of the scrap of wood and about one inch in from the left side.
Attach the nail for the arrow in line with this nail about 3/4 of the way down the wood.
Pull the strands of hair taut so that they are completely straight between the two nails. The arrow should be perpendicular to the strands of hair.
Glue the opposite ends of the hair to the top nail.
Observe the movement of the hair and the pointer. When the humidity drops, the hair will contract and pull the arrow up. When the humidity rises, the arrow will fall.
Listen to the your local weather forecast for the humidity level and compare it with the area your hygrometer indicates. Record the relative humidity at the point your arrow indicates. After several days of recording the levels from the weather forecast, you will soon have your chart filled in and be able to read the meter without the aid of the weatherman. For more accurate results, borrow a hygrometer from a friend for a few days to develop readings for your specific area.