Abstract :
ELECTRIC CURRENTS which are just perceptible are important, as it is essential that the user not get the sensation of electric shock when using electric appliances, hand tools, or other electric equipment.1 Shocks produced by currents near the threshold of perception are generally considered annoying rather than dangerous; however, when such shocks are unexpected, they are startling, and serious accident may result as a secondary effect. For example, an unexpected electric shock, far too feeble to cause injury due to direct effects of the electric current, might produce a sudden movement and cause subsequent contact with a dangerous mechanism, or it might cause loss of balance with an ensuing fall which might cause painful injury.