Capacitive liquid sensor
CA 2007649 C · Owner: Hochstein, Peter A. · Inventors: Hochstein, Peter A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A capacitive level gauge for placement in a container (12) determines the level of substance (14) in the container (12). The gauge (10) includes a measurement capacitor (C1) for measuring level and a reference capacitor (C2) for determining dielectric constant of the substance (14). A controller (34) is responsive to the capacitors (C1, C2) for producing a level signal which simultaneously indicated the level and dielectric constant of the material. The level signal includes a frequency which is representative of dielectric constant and a pulse width representative of level. The gauge (10) supports a fist pair of parallel conductive members (26 28) to, establish the measurement capacitor …
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 January 12, 1990 and granted May 3, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 12, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 12, 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.