| 摘要 |
<p>PCT No. PCT/DE97/01577 Sec. 371 Date Jun. 9, 1999 Sec. 102(e) Date Jun. 9, 1999 PCT Filed Jul. 26, 1997 PCT Pub. No. WO98/12547 PCT Pub. Date Mar. 26, 1998The present invention provides a device for measuring air quality. The device includes at least one sensor with a sensor resistance which is converted via signal processing into an output signal, the gas sensing or air content sensing device having its sensor(s) with electrical resistance that is a function of the air quality, such sensors being connected in an astable flipflop circuit arrangement with a first feedback resistor, a second feedback resistor, a capacitor and a comparator-where the first resistor is coupled between the inverting input and output of the comparator, and the second resistor is coupled between the noninverted input and the output of the comparator, and the sensor(s) is/are coupled between a reference potential and the noninverting input of the comparator. The output signal has a period which is related to the sensor resistance.</p> |
