Capacitance humidity sensor
US5177662A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1992 |
| Grant date | Jan 5, 1993 |
| Priority date | — |
| Expiry date | Feb 5, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/435
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capacitance humidity sensor according to the invention has a film core which is in contact with a pair of polymeric conductive layers bonded to opposite faces of the core. The core is made of a polymeric material having a dielectric constant which varies substantially linearly with humidity, such as a polyimide or polyparabanic acid. The conductive layers are made of a polymeric material, at least a portion of which includes sulfur atoms in the backbone chain and having conductive particles, such as carbon particles, dispersed therein. Such conductive layers provide superior performance and corrosion resistance in comparison to the metal films employed in the prior art and in comparison to cellulosic polymers containing conductive particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.