| 摘要 |
PROBLEM TO BE SOLVED: To prevent a sudden stop due to discontinuity in a resistance heat generating body and generation of a defective products due to the sudden stop in a heat treatment apparatus provided with the resistance heat generating body. SOLUTION: In the heat treatment apparatus, a resistance heat generating body 3 such as a Kanthal line or the like is given an electricity through thyristors 11 to 13 from a transformer 14, the resistance heat generating body 3 is connected with a frequency scanning function 21a that scans the frequency to be applied to the resistance heat generating body 3 at a specified frequency range, and a high-frequency power supply 21 provided with a detection circuit 21b to detect electric characteristics such as reactance or inductance, etc. at that time. The detection circuit 21b is connected with a waveform monitor 22 equipped with a display 22a or the like, which visually displays a waveform showing a change in electric characteristic corresponding to the frequency scanning on the display 22a, and it detects any abnormality of the resistance heat generating body 3 on the basis of a difference of waveform of the resistance heat generating body 3 at normal time and abnormal time (when it is deformed). COPYRIGHT: (C)2004,JPO
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