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:
Nov. 21, 1995
Filed:
Dec. 17, 1993
Applicant:
Inventors:
Takayuki Hasegawa, Yokohama, JP;
Hidehiko Fujioka, Yamato, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; G01N / ;
U.S. Cl.
CPC ...
73 2401 ; 73 3103 ; 73 232 ;
Abstract
The sonic velocity in a chamber which is filled with helium is measured by using ultrasonic waves, and the temperature in the chamber is also measured. Purity information relating to helium gas contained in the chamber is determined on the basis of the measured values of the sonic velocity and the temperature.