Estimation of Current Density Using High-Speed-Camera Recordings in a Model Spark Gap during Surge Currents


  • T. H. Kopp Technische Universität Braunschweig, Institute for High Voltage Technology and Electrical Power Systems
  • E. Peters Technische Universität Braunschweig, Institute for High Voltage Technology and Electrical Power Systems
  • M. Kurrat Technische Universität Braunschweig, Institute for High Voltage Technology and Electrical Power Systems



spark gap, plasma, surge protective device, high speed camera, current density, narrow gap


For experimental investigations of short time plasma in spark gaps, as used in surge protective devices, high-speed camera recordings are used frequently. The analysis of these recordings provides further details regarding the plasma state and distribution. These deduced details are used to assist research and development processes.
To increase the benefit of high-speed camera recordings an empirical model is presented to improve the picture analysis. In this model the recorded radiation intensity is empirically related to the current density within a spark gap. Therefore a specially adapted model spark gap was developed and tested. In this model spark gap areas with homogenous current densities occur. These current densities are determined in the experimental setup through current measurements with separated electrodes. Additionally, the relative radiation intensity between the electrodes is identified using high-speed camera recordings. An empirical correlation between these two measurement values was found and is discussed.
It confirmed that the determined correlation improve the mostly intuitive interpretation of high speed camera recordings in spark gaps.


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