A hygrometer is basically an instrument which is used to measure the relative humidity of the air. It is a tool of great importance in meteorology. With the help of hygrometer science experiment, you can build a simple form of hygrometer at home. This hygrometer is called hair hygrometer. It is based on the principle of fiber absorbing moisture from the atmosphere. The hair gets longer when it absorbs moisture from the atmosphere. The hair becomes shorter when the atmosphere is dry.
Understanding Relative Humidity and Hygrometer :
To perform hygrometer science experiment you will have to follow these simple steps. A flat piece of wood is required (25 cm long and 10 cm wide). Take three eight-inch strands of human hair. Wipe these hair strands with alcohol. This will help in removing residual oils from these hair strands.
Now take a piece of plastic and cut it into a shape of a triangle. This triangular piece of plastic will work as a pointer. To this pointer stick a dime with the help of a tape or gum. Make a hole near the base of this triangle. Between the hole and the dime, glue these hair strands. On the base of the flat wood, attach this pointer with he help of a nail.
Make sure that the pointer is able to move freely. Attach a nail to the top of the wood and secure the free ends of hair strands to it. While doing so, you should make sure that the pointer lies in a perfect horizontal position. Your hygrometer is ready to function. You can place it outdoors to test the changes in humidity.
You may have noticed that the hygrometer science experiment is pretty easy to conduct. Children can use this homemade hygrometer at a science fair. Or they can use it at their homes to check the humidity of atmosphere.