Temperature and metal vapor near the cathode in copper breaking arcs according to spectroscopic measurement

The spatial distribution of the intensities of two spectra are measured usi ng the optical filtering spectroscopic method for breaking arcs in air betw een copper electrodes interrupting circuits of de 50 V and 2.5 to 5.0 A, an d the temperature and the metal-vapor quantity in the cross section of the are column near the cathode are calculated from these intensities. Results show the distribution of spectral intensities in the cross section of the a re column is nearly symmetrical from the ignition to the extinction of the breaking are. The total measured spectral intensities and the peak values o f spectral intensities in the cross section of the are column increase at t he beginning and thereafter decrease gradually with the development of the breaking arc. At the fluctuation of the are voltage wave, which occurs in a copper breaking are, the total values of the measured spectral intensity a nd the peak intensity increase rapidly and the metal-vapor quantity also in creases by a large amount, but change in temperature is slight.