Patent · US Expired

Planar oxygen sensor

US5102525A · kind A · utility

19Cited by
15References
33Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 10, 1990
Grant dateApr 7, 1992
Priority date
Expiry dateDec 10, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N27/404
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A planar oxygen sensor has an insulating substrate, a cathode formed on the insulating substrate generally at the center thereof; another electrode formed on the insulating substrate in a region other than the region of the cathode, a gas permeable membrane stretched to cover these electrodes and having its peripheral portion supported on the insulating substrate, and an electrolytic solution charged between the gas permeable membrane and the insulating substrate. A surface of the cathode is substantially in contact with the gas permeable membrane and is formed at a position higher than the gas permeable membrane support portion of the insulating substrate. A portion of the insulating substrate surface other than the region where the cathode is formed is recessed. Because the layer of electrolytic solution on the cathode is thin, oxygen molecules passing through the gas permeable membrane can immediately serve for the reduction at the cathode, thereby increasing the response speed of the planar oxygen sensor. Also, the amount of electrolytic solution is increased by the recess to extend the life of the sensor.

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