The electric resistance of helmets is measured by applying a high voltage between an electrode placed in salt solution kept inside the helmet and another electrode placed in a salt solution bath in which the helmet is placed in inverted position. The voltage is slowly increased to the specified value and the current passing between the two electrodes measured for evaluating the electrical resistance of the helmet under test.
The JUSTY Electric Resistance Testerfor helmets consists of a plastic container with an acrylic frame placed in its center for keeping the helmet under test on. The two electrodes are held in suitable clamps, one located inside the helmet and the other in the bath.
A high voltage source is provided with the equipment for supplying the test voltage. It consists of a variac, a step-up transformer, a digital voltmeter, and a digital mili-ammeter with a pre-settable tripping currents.
All the parts used in the tester are made from materials that do not get affected by salt solution used for conducting the test.