Paschen’s law in extreme pressure and temperature conditions

Paschen’s law gives the inception voltage for an electrical discharge as a function of the product of gas pressure and the gap distance between two infinite planar electrodes. It is known that deviations from Paschen’s law occur when temperature is increased. Historically two theoretical corrections, the Peek and Dumbar corrections, are proposed to predict the deviation from Paschen’s law by increasing temperature. To carry out an experimental investigation on the deviation from Paschen’s law by increasing temperature a customized system was designed which can operate at temperatures up to 400°C and at pressure up to 1MPa, calculated at room temperature; with an inter-electrode distance between 100μm and 6.6mm and with an error on the inter-electrode distance measurement of 20μm. In this article, firstly, the results from the experimental investigation on the deviation from Paschen’s law at temperature up to 400°C are presented. The results are then compared with theoretical corrections, and finally a theory to explain the results is proposed and discussed