摘要 |
<p>A method of monitoring the degree of exposure of an electric arc within a furnace having a molten charge, eg an arc furnace or ladle furnace, in which characteristic frequency spectra of the waveforms from the supply associated with (a) arc-exposure and (b) arc-submersion are predetermined and in which signals (eg indicative of the arc current) emitted during operation are measured and processed and a comparison effected with a set level established from these characteristic signals whereby to provide an indication of the degree of arc exposure. The predetermined characteristic frequency spectra selected may be the harmonic content of the arc current.</p> |