The Influence of Polarity on High-Voltage Discharges

An experimental investigation of the influence of polarity on high-voltage discharges is reported in this paper. Particular attention is given to those discharges used in high-voltage measurements. A theory of the formation of Lichtenberg figures is given together with experimental evidence upon which it is based. A polarity indicator utilizing visual Lichtenberg figures is described. Results of 60-cycle and impulse tests on various types of gaps are given. It is shown that polarity has a distinct effect upon the sparking voltages of all types of gaps. Impulse measurements with grounded sphere-gaps are shown to be subject to serious error unless the polarity effects are taken into consideration. An explanation of the influence of polarity on spark-over is proposed.