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:
Dec. 26, 1989
Filed:
Dec. 20, 1988
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
2504411 ; 250289 ;
Abstract
An analysis system in which air in a specimen exchange chamber is evacuated by an oil-sealed rotary vacuum pump and which employs electron incorporates a purge gas supply means at the inlet side of the oil-sealed rotary vacuum pump. The purge gas supply means supplies a small quantity of purge gas when the air in the specimen exchange chamber is evacuated to the almost ultimate pressure of the pump.