Measuring arc temperature distribution and its time-evolution based on relative intensity method

Temperature distribution and its time evolution are fundamental physics of arcs occurring during breaking process in electro-mechanic devices, which largely determine contact erosion. Aimed to the highly fluctuating switching arc, we implemented an optical system based on relatively strength of two individual spectrum emitted by the same excited atoms inside the plasma. Light emitted from arc is firstly split into two same beams by using a triangular prism. Then, the beams pass through two narrow-band optical filters with different central wavelengths. Finally, the filtered arcs are projected to the CMOS sensor of a high-speed camera. An algorithm based on relative intensity of two spectrum is developed to calculate the temperature on each pixels after image correction. Test results for typical arcs are also shown.