| 摘要 |
PROBLEM TO BE SOLVED: To measure smell with a simple constitution using a general-purpose temp. sensor and a humidity sensor by outputting a warning signal when the generation of a drift is expected by fluctuations of temp. and humidity. SOLUTION: A measuring cell 9 is reduced in pressure by a pump 8 to suck zero point corrected air and this air is measured by a smell sensor 1, a temp. sensor 2 ad a humidity sensor 3 to calibrate a zero point. At the same time, a zero point calibration signal 103 is inputted to a counter circuit 13 and sample hold circuits 10a, 10b. The circuit 13 sets the count value at that time to zero and the circuits 10a, 10b hold temp. and humidity at that time. Air 100 to be measured is sucked to measure the smell, temp. and humidity of the air 100 by the respective sensors. A comparator 11a(11b) compares the output of the sensor 2(3) with the output of the circuit 10a(10b) and, when the comparison result exceeds a definite value, the outputs are set to a high level and a logical circuit 12 outputs a warning signal 104. Therefore, it is unnecessary to actually correct temp. and humidity and temp. and humidity drift simulators are dispensed with and the constitution becomes simple. |
