Daylight corona discharge imager

Ofil Ltd. has developed a bispectral visible-solar blind UV video imager (DayCor Camera), that is suitable for corona and partial discharges imaging in full daylight. This system detects and locates weak corona signals in full daylight by overlaying a UV video image of the corona on a visible video image of the surrounding scene. The corona that emits radiation only in the UV is visualized with the surrounding scene as background. The ability of the DayCor camera to operate in full daylight derives from the careful control of the spectral response of its UV imager, which is totally solar blind and insensitive to solar radiation. The solar blindness is achieved by using a special filter, developed by Ofil that is transparent in the solar blind UV band and is completely opaque to solar radiation. The DayCor camera detects and locates corona at noontime on HV transmission line insulators from a distance up to 100 meters with good signal to background ratio. The concept of the method is explained and illustrated in this presentation