Humidity sensor

Abstract

Abstract PURPOSE:To increase the dynamic range of a humidity sensor output by making a semiconductor thin plate flex by utilizing the expansion or shrinkage of a humidity-sensitive expansible thin film and transducing the quantity of the deflection into an electric signal. CONSTITUTION:A silicone diaphragm type pressure sensor pellet 1 utilizes a semiconductor piezoelectric effect, and the diaphragm 3 has P type piezoelectric resistance areas 4a-4d by diffusion and a wiring path 5 vapor-deposited. The humidity-sensitive expansible film 9 is made of nylon and adhered to the reverse surface of the diaphragm 3. A case 10 fixed to a header 6 covers the sensor pellet 1 airtightly and the film 9 contacts a measurement atmosphere through the center opening 11 of the header 6. When the film 9 expands or shrinks according to humidity, the quantity of deflection of the diaphragm 3 varies and the piezoelectric resistance areas 4a-4d vary in resistance value accordingly, so that the output voltage of the resistance bridge indicates the quantity of deflection of the diaphragm 3, i.e. the humidity.

Inventors

• 👤 Yoshio Miyai
• 👤 宮井　良雄
• 👤 Sadao Sakamoto
• 👤 阪本　貞夫
• 👤 Yasuhiro Takeda
• 👤 安弘 武田

Bibliographic Details