| 摘要 |
<p>PURPOSE:To stably operate a plasma arc furnace by quickening time response, preventing the delay of an arc control time, and the direct state quantity of an arc. CONSTITUTION:Radiant light from an arc furnace 4 for heating and melting a heated object 6 is first imaged at the position of a screen 8 via a lens 7 and received by a single or a plurality of thermal detectors 10 after passing an aperture lens 9. As a result, the light is converted to an electrical signal and the absolute value of radiation density is obtained. Concurrent with the acquisition of the absolute value of the radiation density. the radiant light from the arc furnace 4 is reflected by a semi-transparent mirror 11 and passes an optical filter 12 selectively transmitting a wavelength having no line spectrum characteristic of each gaseous species, among long wavelengths enough for taking the correlation of total radiation intensity. Thereafter, spatial distribution is detected by a quick response type two-dimensional image pickup device 13. From this relative intensity the absolute radiation intensity is obtained by a device 14 using the signal from the detector 10 of the absolute value.</p> |
