Patent · US Expired

Method and device for compensating temperature-dependent characteristic changes in ion-sensitive FET transducer

US4641249A · kind A · utility

29Cited by
8References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 19, 1984
Grant dateFeb 3, 1987
Priority date
Expiry dateJun 19, 2004

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N27/4148
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An ion activity monitoring device is disclosed, having a semi-conductor device including an ion-sensitive field-effect transistor, for detecting the activity of ions in a liquid medium of interest, and a temperature sensor, for detecting the temperature of the liquid medium of interest, a constant current circuit for supplying a drain current of a particular value to the transistor, and a processing circuit for calculating the concentration of the ions in the liquid medium of interest. The drain current is of a value satisfying the relationship of .vertline.Id/.beta..vertline..ltoreq.0.10 volt.sup.2, wherein Id represents the drain current and .beta. represents the channel characteristic value of the ion-sensitive field-effect transistor. A method for operating the transistor is also disclosed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.