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.

Date of Patent:
Nov. 16, 1999

Filed:

Apr. 16, 1996
Applicant:
Inventors:

Qingcheng Bao, Tempe, AZ (US);

Ian Sorensen, Phoenix, AZ (US);

William Glaunsinger, Chandler, AZ (US);

Assignee:

Arizona Baord of Regents, Tempe, AZ (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
436151 ; 204431 ; 73 232 ; 73 2503 ; 7333505 ;
Abstract

A method and apparatus for rapidly and continuously restoring the sensing capacity of thin film sensing elements includes passing a sufficient electrical current through the sensing element to remove from the element selected components from a fluid sample in contact with the sensing element that have an affinity for and are adsorbed and accumulated onto the surface of the sensing element. The passing of current through the sensing element can be accomplished either by applying a constant voltage across the sensing element or by forcing a constant current through the sensing element. The restoration technique removes the components from the sensing element by a combination of resistive heating of the element and electron bombardment of the components on the surface of the element. Moreover, to prevent possible rupture of the sensing element due to electromigration, the current may be alternated in a first direction and then in a second and opposite direction through the sensing element in sequential runs of equal predetermined time intervals.


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