Corona Surveys

Dangerous Suspension Insulator 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 that 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 nighttime 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 location.

This pad-mount switch is near flashover! The green clouds are corona that is ionizing the air and about to cause a blowup.

Seeing the Invisible

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.
The 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.