Digital sensing device
US4034609A · kind A · utility
Inventor
Key dates
| Filing date | Jan 2, 1976 |
| Grant date | Jul 12, 1977 |
| Priority date | — |
| Expiry date | Jan 2, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01W1/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A multiple laminae humidity sensing device for visually indicating changes in relative humidity including a moisture impermeable transparent support layer having a viewing side and a sensing side opposite said viewing side; an indicator layer with a plurality of filter cells, each including a transparent carrier material and an inorganic salt composition dispersed in the transparent carrier material that provides a known visible color response to changes in relative humidity on the sensing side of the support layer and a moisture permeable reflective layer behind the indicator layer so that light passing through the support layer and the indicator layer is reflected back through the indicator layer and the support layer through the viewing side of the support layer so as to be readily visible from the viewing side of the support layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.