Humidity detector
US4723439A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 1986 |
| Grant date | Feb 9, 1988 |
| Priority date | — |
| Expiry date | Nov 5, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/121
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A humidity detector which is disclosed herein includes a humidity sensing element consisting of a heating resistance wire coil and a humidity sensing portion of a metal oxide or metal oxides sintered on the coil with the opposite ends of the coil being exposed, a heating circuit for energizing the coil to increase the temperature of the humidity sensing portion to a level higher than the temperature in a measuring atmosphere, and a resistance variation detecting circuit for detecting the variation in resistance between the opposite ends of the coil depending upon the humidity contained in the measuring atmosphere. The metal oxide may be Al2O3 or a mixture of Al2O3 with at least one selected from the group consisting of SnO2, ZnO, TiO2 and MgO.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.