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:
Apr. 01, 1986
Filed:
Oct. 31, 1984
Applicant:
Inventor:
John F Zettler, Stow, MA (US);
Assignee:
Varian Associates, Inc., Palo Alto, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01L / ;
U.S. Cl.
CPC ...
73755 ; 374164 ; 374179 ;
Abstract
A thermocouple pressure gauging system for measuring partial vacuum is provided which uses time multiplexing to alternately heat the thermocouple to constant temperature and then measure the EMF from thermocouple with heating current off. A signal proportional to pressure is derived from the heating duty cycle. The pressure signal is in turn used to derive a reference signal which is compared to the EMF from the thermocouple to control the heating of the thermocouple.