● Humidity detector detects the presence of moisture in our hands, and gives you indicator with the help glowing LED's.
● This Humidity detector circuit can be used to test the stress, emotion or can be used as lie detector. As emotion and stress is not reflected by heart beat, blood pressure and body temperature but in that case skin moisture also increases. And when skin become moist its resistance decreases.
● When a person speak lie its body resistance decreases. Therefore skin resistance is a good indicator for measuring stress level.
● When a person speaks lie physiology changes occur because of that body resistance decreases and now you can compare it with the result for normal question.
This Humidity detector circuit is based on two IC namely CA3130 and LM3914 and LED’s to show you the stress meter with few more components.