Critical angle refractometer for measuring refractive index of seawater
CA 2054887 A1 · Owner: Newtech Instruments Limited · Inventors: Dittman, Richard D.; Dittman, Richard D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A high precision linear solid state opto-electronic critical angle refractometer which is adapted to continuously measure the refractive index of a liquid over a narrow range of refractive indices when immersed into liquid being measured. The device is adapted for use in both industrial and oceanic remote sensing applications. The device is compact and is comprised of a broad beam monochromatic infra-red semiconductor light source a, planar prism with one measuring plane and a reflective plane perpendicular to the measuring surface, and a small aperture semiconductor light detector shielded by an infra-red band-pass optical filter. The device is capable of measuring small changes in …
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 November 6, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 6, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 6, 2013.
- 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.