The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 1987
Filed:
Aug. 17, 1984
Hendrik H vd. Vlekkert, Groningen, NL;
Nicolaas F de Rooy, Bole, CH;
Sentron v.o.f., Roden, NL;
Abstract
The apparatus (10) for determining the activity of an ion (pIon) in a liquid (16) comprises a measuring circuit (10) including an ion sensitive field effect transistor (ISFET 12), a reference electrode (32) adjacent the ISFET (12), a temperature sensor (34) adjacent the ISFET (12), amplifiers (22 and 38) coupled to the ISFET (12) and temperature sensor (34), and control, computing and memory circuits (30, 44, and 46) coupled to the amplifiers and operable to maintain two of the following three parameters, V.sub.gs (gate-source potential), V.sub.ds (drain-source potential) and I.sub.D (drain-source current) at a constant value so that the third parameter can be used for determining the ion activity or pIon. The pIon sensitivity of the apparatus (10), as a function of temperature and/or the variation of the drain-source current, I.sub.D, as a function of the temperature are controlled by controlling the V.sub.gs so that the pIon can be calculated from a formula stored in the memory (46 ).
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile