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:
May. 31, 1988
Filed:
Mar. 10, 1987
Applicant:
Inventor:
Hisao Hojoh, Musashino, JP;
Assignee:
Seiko Instruments Inc., Tokyo, JP;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01L / ;
U.S. Cl.
CPC ...
73702 ; 73714 ; 73756 ; 324460 ;
Abstract
Regarding a gas pressure gage for measuring a gas pressure in a vacuum chamber of a semiconductor element manufacturing apparatus, or the like, the present invention has made it possible to attain a small-sized and unitary gas pressure gage and to implement a thorough measurement of gas pressure from the atmospheric pressure to a high vacuum of about 10.sup.-10 Torr, by mounting both a mechanical vibrator type pressure gage and an ionization type pressure gage on a flange provided for fitting a chamber and by providing a control circuit for making the former gage operate in a low-vacuum region and the latter in a high-vacuum region.