| 摘要 |
PROBLEM TO BE SOLVED: To widen a measurable range, to reduce a cost, and attain high performance and high precision, in an environment measuring instrument for measuring an environmental condition such as a temperature and humidity. SOLUTION: A thermistor 103 of which the resistance value is varied by the temperature, and a humidity sensor 104 of which the resistance value is varied by the humidity are provided as detecting elements of which the resistance values are varied by an environment, and capacitors 114, 115 are connected in series to the humidity sensor 104. A detecting means 113 is provided to acquire a detection signal of the environment (humidity) in response to the resistance value of the humidity sensor 104, based on an output when charging the capacitor 115 through the humidity sensor 104. Oscillation circuits 110, 111 and a change-over switch 112 are provided to impress a prescribed oscillation output to the humidity sensor 104 through resistances 116, 117, and a frequency of the oscillation output impressed to the humidity sensor 104 is switched in response to the resistance value of the humidity sensor 104. COPYRIGHT: (C)2005,JPO&NCIPI
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