Making a product “safe” requires an understanding of “hazards” that exist in each electrical product. Electrical shock is one of the four fundamental hazards. Because of that, it must be a part of any product electrical safety evaluation. Even though a product requires an electrical power source and uses electrical or electronic components, it should not present an electrical shock hazard to the user.
Ground bond or earth continuity testing prevents electrical shock hazards. Similarly to a fault to earth, test instruments generate a high current. The standard requires that the resistance between protective earth and any conductive surface on the equipment does not exceed 0,1 Ohm. The test is performed by applying a DC current between the conductive surface and protective earth. By measuring the voltage drop, it calculates the resistance.