Optical humidity sensor
US4641524A · kind A · utility
13Cited by
6References
17Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 15, 1985 |
| Grant date | Feb 10, 1987 |
| Priority date | — |
| Expiry date | Aug 15, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/21
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical dielectric humidity sensor which includes a dielectric mirror having multiple alternating layers of two porous water-adsorbent dielectric materials with differing indices of refraction carried by a translucent substrate. A narrow-band polarized light source is positioned to direct light energy onto the mirror, and detectors are positioned to receive light energy transmitted through and reflected by the mirror. A ratiometer indicates humidity in the atmosphere which surrounds the dielectric mirror as a function of a ratio of light energies incident on the detectors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.