The spatial distribution of temperature in a cross section of arc column near cathode contact

摘要

By measuring simultaneously the spatial distributions of two spectral intensities with AgI-421 nm and AgI-546 nm spectrum in a cross section of an arc column by two sets assembled with a CCD color linear image sensor and a combination of optical filters, the authors have estimated the radial distributions of temperature of arc column between separating Ag, AgCdO and AgSnO/sub 2/ contacts in DC 50 V and 2.5, 3.3 and 5.0 A circuits. The peak temperature in the cross section of the arc column near the cathode contact between Ag contacts is at the axis, and its value is dependent on the arc duration. For the duration of metallic phase arc, the peak temperature is high, for the metallic-gaseous transition period it goes down temporarily, for the beginning of the gaseous phase arc it goes up, and for the duration of gaseous phase arc it gradually goes down. The temperature difference between the center and at the fringe of the arc column becomes low with development of the breaking arc. The higher the interrupted current is, the higher the peak temperatures of the arc column at the terminal arc become. The arc temperatures in AgCdO and AgSnO/sub 2/ contacts turn into the same feature in Ag contacts.