Kawasaki Steel Corporation

Kazuo Arai

Tomohiro Marui

Masayuki Onishi

Saburo Moriwaki

Hiroshi Nomura

Kazuya Asano

Hiromitsu Yamanaka

Mototatsu Sugizawa

Takayuki Kaji

Yuki Nabeshima

Shuji Tanaka

Masaki Takashi

Michio Ibaraki

A method and apparatus are disclosed for controlling a physical property such as deposited film thickness to a desired value of control in a high temperature process using a desired emissivity power ratio and an emissivity power ratio measured from detected radiation energy. The measured emissivity power ratio is obtained on-line from detection signals of radiation sensors. A desired value of control is converted to the desired emissivity power ratio using predetermined relationships established by theory or experiment. The desired emissivity power ratio and the measured emissivity power ratio are compared to achieve the desired value of control.

Method and apparatus for process control of material emitting radiation

Radiated light with a specified wavelength from a material is detected and a first parameter corresponding to the emissivity ratio is obtained from the plurality of detection signals. Since the emissivity takes on different values according to the condition of the surface of the material, the first parameter changes depending on the surface condition of the material. There is a correlation between a physical value indicating a condition of the material surface and the first parameter. The correlation remains equivalent even if a second parameter corresponding to the physical value is used instead of the physical value itself (for example, an optical physical value such as reflectivity and absorptivity, the thickness of a film formed on the material surface, the surface roughness, and the degree of galvannealing). As an example of the parameter corresponding to the physical value, there is the logarithmic ratio between emissivities (ln .epsilon..sub.a /ln .epsilon..sub.b) corresponding to the temperature in the vicinity of the surface. Therefore, a second parameter can be obtained on the basis of the correlation and a physical value can be obtained. When the emissivity or logarithmic emissivity ratio is used as the second parameter, the temperature in the vicinity of the material surface can be obtained from the second parameter and the plurality of detection signals.

Surface condition measurement apparatus

Molten metal level control method and device for continuous casting

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Chiba, Japan

Kazuo Arai