| 摘要 |
PROBLEM TO BE SOLVED: To measure material temperature T based on supplied electric power P by a simple structure in a case of directly heating resistance by using a rectifier DC power supply A<SB>2</SB>. SOLUTION: An effective voltage value measuring instrument 12 and an average voltage value measuring instrument 13 are provided between two electrodes 2 and 2. An average voltage value V<SB>L</SB>a between the two electrodes, an average current value Ioa in a DC power supply device, and an effective voltage value V<SB>L</SB>r between the two electrodes are fed into a computing unit 14. In the computing unit, the voltage value V<SB>L</SB>a is divided by the current value Ioa (V<SB>L</SB>a/Ioa) to calculate a resistance value R<SB>L</SB>of a material (a) layer. The resistance value and the voltage value V<SB>L</SB>r are used to calculate electric power P=((V<SB>L</SB>r)<SP>2</SP>/R<SB>L</SB>) and electric energy Wt. Based on the electric energy Wt, a temperature rise Ta is calculated from calorie Q/(m×C)=Wt×860×4.186×10<SP>-3</SP>/(m×C) to measure material temperature T. Based on the measured temperature T, an output current I<SB>2</SB>is steplessly linear-controlled by means of thyristor phase control using a rectifier 8, thereby varying the supplied power P to obtain required temperature of the material (a). COPYRIGHT: (C)2011,JPO&INPIT
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