Gas detector
CA 2637306 C · Owner: Tulip, John · Inventors: Tulip, John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A gas detector of gas in a target zone has a transmitter of frequency modulated light and a receiver. In the receiver a homodyne detection circuit mixes a detected signal with a reference signal at one of the modulation frequencies where the reference signal has been derived from light that has passed through the target zone. The homodyne detection circuit includes a bandpass filter amplifier, phase lock loop and phase shifter. Etalon fringes are reduced by moving them to high frequencies and filtering them out. Gas density is measured by comparison of the detected signal from the target zone with a signal from a gas reference cell. A method of detecting gas includes transmitting frequency …
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 16, 1996 and granted January 8, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 16, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 16, 2018.
- 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.