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US 4,319,485 AGranted
Temperature.multidot.humidity detecting apparatus
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsJiro Terada, Tsuneharu Nitta
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Abstract
A temperature.multidot.humidity detecting apparatus which can detect the temperature and humidity with a single element. The temperature.multidot.humidity detecting element of the present invention varies its impedance value with respect to variations in the temperature and humidity, and the temperature.multidot.humidity detecting apparatus is adapted to detect the variations in the temperature.multidot.humidity detecting element impedance to determine the temperature and humidity.
Claims4
A temperature.multidot.humidity detecting apparatus comprising:
- an element in which a pair of electrodes having terminals are provided on a dielectric portion, said dielectric varying in impedance in accordance with variations in the ambient temperature and humidity due to the large temperature dependency of the dielectric constant thereof and the large variation in resistance value due to the vapor absorption thereof;
- a load impedance whose impedance selectively varies in accordance with variations in frequency;
- and
- an oscillating circuit power source, said load impedance and said oscillating circuit power source being connected in series with said electrode terminals of said element, the temperature and humidity being detected by selecting respective oscillating frequencies of said oscillating circuit power source.
1 more element
Dependencies are inferred from the claim text.