| 摘要 |
PROBLEM TO BE SOLVED: To provide a state monitoring device by which the disconnection of a temperature sensor and excess a temperature rise of an object for monitoring are discriminated and recognized. SOLUTION: The change ratioΔPV of a temperature value PV is calculated, and a change ratio threshold Th is set on the basis of the maximum value of the change ratioΔPV in normal time. Then, whether or not the temperature value PV exceeds a predetermined upper limit value Rh is decided, when the temperature value PV exceeding the upper limit value Rh is detected, whether or not the change ratioΔPV immediately before that exceeds the change ratio threshold Th is decided, when the change ratioΔPV exceeding the change ratio threshold Th is detected, a disconnection signal is outputted, and when the change ratioΔPV does not exceed the change ratio threshold Th, an over signal is outputted. COPYRIGHT: (C)2009,JPO&INPIT
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