All of the above gap lengths and electrode geometries are encountered in VLF/LF equipment. A correction factor for the breakdown voltage as a function of humidity has been developed. Because of the large difference on the breakdown characteristics at 30 kHz when compared to power frequencies (50/60 Hz) and dc, special attention is to be paid to the design of VLF/LF equipment. The extensive data available for power frequencies and dc for non-uniform fields cannot be readily applied.