Photographic Method for Determining the Burning Time of an Electric Arc

The paper presents a comparison of two methods for determining the burning time of an electric arc in a vacuum chamber: the classic oscilloscope method and the author’s own photographic analysis using an ultra-high-speed camera. A specially designed laboratory station enabled precise recording of electrical and optical parameters during switching operations conducted at different pressures in the discharge chamber. The photographic method consisted of a time-lapse analysis of the ignition and extinction of the arc using dedicated software to precisely determine its duration based on the recorded images. In total, five repeated measurements were performed for each pressure value. All the results were subjected to a detailed statistical analysis, including the determination of standard deviations and confidence intervals. The reported mean relative error for the new photographic method did not exceed 1.12%. The developed photographic method proved to be a reliable tool for assessing the duration of the arc, while also enabling a detailed analysis of the dynamics of arc channel development. Possible applications include laboratory testing and diagnostics of switching devices, especially where traditional measurement methods are difficult to apply.