CTL has Surge Test Facility upto 20 KV & Impulse Test Facility having different waveshapes like 1.2/50 µs , 10/700 µs etc. These tests are covered under the following Indian and International standards: IS 616, IEC 60065, IS 13252, IEC 60950, IS 302 etc.

To represent surges generated due to lightning, the IEC Standard impulse wave of 1.2/50
s wave is generally used. By the use of spark gaps, conditions occurring on the flash over to line are simulated. The total duration of a single lightning strike os about 100
s, although the total duration of the lightning stroke may be a few seconds.

These tests relate to the immunity requirements for equipment to unidirectional surges caused by overvoltages from switching and lightning transients. Several test levels are defined which relate to different environment and installation conditions. These requirements are developed for and are applicable to electrical and electronic equipment.