To measure the approximate electrostatic potential to which your body is charged.
Van de Graaff generator with ground sphere, electrostatic voltmeter, point for electrostatic discharge, wires.
The volunteer, standing on a styrofoam insulating pad and connected to an electrostatic voltmeter, holds a discharge point close to the dome of a Van de Graaff generator. The charge on the person is measured by the voltmeter. The point discharge allows the person to be charged but prevents large sparks.