Insulation resistance

The insulation resistance is the resistance in ohms of wires, cables and electrical equipment. It is important to guard against electric shocks and avoid equipment damage from accidental discharges. The method of measuring the insulation resistance is to test and assess the state of the isolation (head and body.)

An insulation resistance (IR) test measures the total resistance between any two points separated by electrical insulation. The test, therefore, determines how effective the dielectric (insulation) is in resisting the flow of electrical current. Such tests are useful for checking the quality of insulation, not only when a product is first manufactured but also over time as the product is used.