Sparking potentials of saturated hydrocarbon gases

Abstract

The Paschen curves of sparking potential as a function of the pressure × gap length product (pd) are given for normal pentane, hexane, heptane, octane and decane. The measurements of sparking potential have been made from pd about 30 Torr cm through the minimum sparking potential about 1 Torr cm to approximately 3 × 10−3 Torr cm. A previous empirical equation giving the sparking potential for values of pd greater than minimum sparking potential has been modified by the addition of two constants and an extra term, so that it now fits the Paschen curves for the whole of the extended range of the measurements while retaining the constants introduced by previous workers. Values of the constants are tabulated for the hydrocarbons listed above and a detailed comparison between the sparking potentials calculated from the equation and experimental results is given for n-octane.