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. 05, 2000
Filed:
Feb. 04, 1998
Abstract
A plate-type NO.sub.x gas sensor having a WO.sub.3 sensing film which are capable of preventing temperature variation of a sensing thin film depending on gas flow to decrease heat loss thereof, whereby extending the life span of batteries of a portable gas sensor. The plate-type NO.sub.x gas sensor includes a Pt thin film electrode formed on a front surface of an alumina substrate, a tungsten oxide thin film for sensing NO.sub.x gas deposited on the front surface of the substrate on which the Pt thin film electrode is formed, a heater formed on a back surface of the alumina substrate for holding a portion of the tungsten oxide thin film for sensing NO.sub.x gas within a predetermined temperature range, a conducting wire for connecting between the Pt thin film electrode and the heater and a sheet made of at least one material selected from a group composed of Al.sub.2 O.sub.3, mullite, codierite, magnesia and zirconia, coated on the back surface of the substrate on which the heater is formed, for burying completely the heater from an exterior atmosphere to protect the heat dissipation. The NO.sub.x gas sensor may be fabricated as a bar type and also have a catalytic layer on the sensing layer to enhance the sensing characteristics of the sensor.