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. 16, 1993
Filed:
Mar. 27, 1992
Applicant:
Inventors:
James J McAndrew, Lockport, IL (US);
Michael D Brandt, Chicago, IL (US);
Assignee:
American Air Liquide, Walnut Creek, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01F / ;
U.S. Cl.
CPC ...
137606 ; 137100 ; 137896 ;
Abstract
An apparatus and method are provided for preparing low concentration gas phase calibration standards. The flows of a standard mixture of impurity in a gas and a dilution gas are controlled by regulating the pressure upstream of respective calibrated orifices. The pressures of the gas flows are regulated such that a critical flow condition is maintained through the orifices. The two flows are then combined to obtain a known dilution of the impurity in the gas.