Capacitance humidity sensor
CA 2066762 C · Owner: Thoma, Paul E. · Inventors: Colla, Jeannine O.; Thoma, Paul E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A capacitance humidity sensor according to the invention has a dielectric film core (11) which is in contact with a pair of polymeric conductive layers (12. 13) bonded to opposite faces to the core (11). The dielectric core (11) is made of a polymeric material having a dielectric constant which varies substantially linearly with humidity such as polyimide or polyparabanic acid. The conductive layers (12, 13) are made of a polymeric material having conductive particles such as carbon particles, dispersed, therein. Such conductive layers (12 13) provide superior performance and corrosion resistance in comparison to the metal films commonly employed in the prior art.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed September 27, 1990 and granted May 11, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 27, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.