| 摘要 |
PROBLEM TO BE SOLVED: To easily, surely and timely sense damage and deterioration. SOLUTION: A failure sensing apparatus 1a for gas sensor is constituted by being provided with a reference voltage applying circuit 30 for applying a predetermined reference voltage to a series circuit 29 comprising a detection element 21, a temperature compensation element 22 of the gas sensor 1, and a dummy element 23 equivalent to the detection element 21 serially connected; a detection circuit 31 for detecting a voltage between terminals of the detection element 21; and a control circuit 32. A failure judging part 34 of the control circuit 32 judges whether a detected value of the voltage between the terminals of the detection element 21 is a predetermined failure determination value or less set based on the reference voltage applied to the series circuit 29. If YES, it judges that the gas sensor 1 is out of order and an instruction signal for instructing to switch an output is outputted. If NO, it judges that the gas sensor 1 is normal. An output switching part 35 outputs a predetermined output value to an output circuit 33 instead of the detected value of the voltage between the terminals inputted from the detection circuit 31 based on the instruction signal for switching the output. COPYRIGHT: (C)2004,JPO
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