Spectroscopic Imaging Observation of Break Arcs using a High-speed Camera

Break arcs occurring between electrical contacts are observed in DC42V resistive circuit using a high-speed camera. Materials of contact pairs are Ag or Ag/ZnO. The break current is 10A. Spectroscopic images are obtained using the high-speed camera with optical band pass filters. The filters are attached on the lens to observe only the Agl 521 nm or ZnI 481 nm spectrum images, respectively. The time evolutions of these images are discussed. The following results are obtained. For Ag/ZnO contacts, the intensity of the images of Ag spectrum line is almost same for the cases of the long and short arc-durations. On the other hand, the intensity of Zn spectrum line for the case of short arc-duration is higher than that of long arc-duration. These results show the existence of Ag rich layer on the contact surface for the case of long arc-duration and the higher evaporation rate of ZnO for the case of short arc-duration.