The insulation resistance tester is completed by using a special test instrument. The most commonly used test instrument is a megohmmeter, but other types of instruments can also be used to check the integrity of different insulation types.

When the insulation resistance tester is working, it generates high voltage by itself, and the measurement object is electrical equipment, so it must be used correctly. Otherwise, it will cause personal or equipment accidents. Before using the insulation resistance tester, you must first make the following preparations:

(1) Before measurement, the power supply of the equipment under test must be cut off and short-circuited to ground. Never allow the equipment to be charged for measurement to ensure the safety of persons and equipment.

(2) For equipment that may induce high voltage. This possibility must be eliminated before the measurement can be performed.

(3) The surface of the test object should be clean to reduce contact resistance. Ensure the accuracy of the measurement results.

(4) Check whether the megohmmeter is in normal working condition before measurement. Mainly check the position of "0" and "∞", that is, shake the handle of the hand-cranked generator. Make the motor reach the rated speed. When the megohmmeter is short-circuited, the pointer should point to the "0" position. When the circuit is open, the pointer should point to the "∞" position.

(5) The megohmmeter should be placed in a stable and firm place when using it. And stay away from large external current conductors and external magnetic fields.