Laboratory studies of corona emissions from air terminals

This paper presents some of the results obtained from a systematic series of laboratory investigations into the corona emission characteristics of air terminals. Two particular aspects are considered, namely the effect on corona emission of changing the distance between the tip of the air terminal and the overhead energized electrode, and the relationship between the two fundamental corona parameters ('amplitude coefficient' and onset electric field) and the height of the air terminal above a ground plane. The implications of the results for lightning protection designs are discussed.