Coupon monitor for cathodic protection system
CA 2258360 C · Owner: Lawson, Kurt M. · Inventors: Thompson, Neil G.; Lawson, Kurt M.; Caudill, Dan L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An automated coupon monitor for detecting the electrical parameters associated with a pipe a coupon, and a reference electrode utilized with a cathodic protection system. A voltage detector circuit has its output applied to a pair of sample and hold circuits one, for recording E OFF and the other for recording E ON. Series connected between the coupon and the pipe is a zero resistance current detector circuit and an interrupter switch for measuring the pipe-coupon current and periodically interrupting that current to permit measurement, sampling and storing of E OFF. The sample and hold circuits and the interrupter switch are controlled by a microprocessor controller. The circuit provides …
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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 11, 1999 and granted October 23, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 11, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 11, 2021.
- 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.