When you feel nervous, excited, surprised, or otherwise aroused, you experience galvanic skin response (GSR). Your sweat glands, in responses to adrenaline and other hormones, start to release micro pulses of sweat. GSR is one component of polygraph tests because it’s an indicator of how nervous a question makes you feel. The increase in sweat causes an uptick in the electrical conductivity of your skin. The Truth Meter, a project from MAKE Volume 26 and Make: Projects is a simple circuit that you can make yourself that will indicate sudden changes in your GSR. So if you’re sleuthing to find out who left the empty milk carton in the refrigerator and your prime suspect does nothing but deny accusations, pull out MAKE Volume 26 and create your own Truth Meter.
In the Maker Shed: Galvanic Skin Response Kit