Detection and measurement of discharges in gaseous cavities in solid dielectrics under direct-voltage conditions

A technique for detecting and measuring discharges in gaseous cavities in solid dielectrics under direct-voltage conditions has been developed, whereby the voltage pulses arising from the discharges are amplified, shaped and recorded on magnetic tape. This tape is afterwards played back through a pulse scaler set to count above any desired level. The system is calibrated by feeding known voltages into the circuit from a pulse generator. An example of this use of a tape recorder is provided by an experiment on a cylindrical air-filled cavity, of known dimensions, in polythene. It is considered that the technique will be of value in investigating gaseous discharge phenomena in a wide range of insulating materials, and may also be applicable to complete insulating systems.