Thermal imaging technique is an advanced technology for diagnosing the hot spots in substations, ransmission lines and distribution network, which plays a key role in finding, preventing and handling the accident in power industry. Infrared technology gives us the ability to "see" and measure temperatures on defective components and the normal wear, chemical contamination, corrosion, fatigue and faulty assembly in many electrical systems. It helps quickly locate hot spots, determine the severity of the problem, and help establish the time frame in which the equipment should be repaired.