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:
Feb. 02, 1982
Filed:
Nov. 19, 1979
Applicant:
Inventors:
Ronald M Paitich, Los Altos, CA (US);
Donald D Briglia, Palo Alto, CA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
324460 ; 324462 ;
Abstract
The operating range of an ionization tube vacuum gauge is increased by applying at least two different bias voltages to the tube and measuring ion current for the two bias voltages. The ratio of the ion currents indicates vacuum pressure in the range of 10.sup.-1 to above 2 Torr. An ionization tube vacuum gauge provides a pressure read-out by the linear ion current response of an ionization tube between 10.sup.-10 Torr and 10.sup.-2 Torr. The non-linearity of the ion current response between 10.sup.-2 Torr and 10.sup.-1 Torr is compensated by a non-linear amplifier. Above 10.sup.-1 Torr the ratio of ion currents is utilized for determining pressure.