Corona Imaging Surveys
Corona radiates energy in the ultraviolet (UV) region of the spectrum, which is invisible to the human eye. Our Corona Camera operates in the ultra-violet spectrum, enabling our skilled technicians to obtain a visible image of surface corona problems during complete daylight conditions, while your equipment remains in service.
Dangerous suspension insulator corona activity.This pad-mount switch is near flashover. The green clouds are corona that is ionizing the air and about to cause a blowup.
Corona images are used to generate a technical report with images of problem areas. The information contained in the report is then used to recommend corrective actions necessary to prevent future failures. In a similar manner that infrared technology detects faulty electrical connections, corona imaging detects dangerous corona activity.
Level I Corona Surveys are performed using ultrasonic detection equipment, with parabolic-dish signal concentrators and laser pointers which help pinpoint location. This method provides quick ‘go/no go’ results, which alert the facility owner that potential corona problems may be present.
We perform Level II Corona Surveys using daylight corona cameras that allow us to view and record corona activity on insulators and conductors. The surveys can be performed during daylight or night-time conditions and determine the precise location and magnitude of the corona activity, so that condition assessment decisions can be made.
This type of testing is ideal for outdoor substations and transmission and distribution lines, but also has been used to pinpoint switchgear surface partial discharge locations.