Insufficient insulation between conductors can cause electrical hazards and severe damage to other electrical equipment. This is why adequate testing of insulators is necessary to avoid unexpected circumstances. Using an insulation tester can help detect problems in insulators within a few minutes.
The most common tester used for testing insulation resistance is a Megger S1-554 5 KV tester. TheMegger insulation tester can measure resistances up to 15 terra ohms. It features various diagnostic tests such as dielectric discharge, dielectric absorption ratio, step voltage and polarization index. It has a 4 milli ampere noise rejection and noise filtering so any interference will not affect the resistance reading. It has a variable test voltage which ranges from 50 volts to 5000 volts. It has a back lit LCD screen making it easy for you to use this equipment in poorly lit places. The LCD displays information like voltage, leakage current, resistance, capacitance, time constant and battery gauge. It has a built-in timer that displays the duration of the test. It also has a RS232 port so you can attach the tester to a computer for recalibration.