Liquid sensor having thermistors
CA 2104424 C · Owner: Intertechnique · Inventors: Le Pimpec, Michel
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A sensor for detecting whether liquid is present at a location in a tank, comprises a probe placed at the location, containing a negative temperature coefficient resistor (NTC) and a positive temperature coefficient resistor (PTC) mutually connected in series relation. The positive temperature coefficient resistor exhibits a progressive resistance variation responsive to temperature change. An electrical power source delivers a constant electric current to the probe. The detector further comprises a comparator for comparing the total resistance of the serially mounted resistors with a threshold.
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 August 19, 1993 and granted November 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 19, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 19, 2015.
- 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.