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:
Apr. 22, 1980
Filed:
Nov. 02, 1978
Applicant:
Inventors:
John F Graham, Perivale, GB;
Donald Hardy, Wembley, GB;
Assignee:
American Filtrona Corporation, Richmond, VA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
73 38 ; 73159 ;
Abstract
The present invention provides a method and apparatus for evaluating the porosity of a sheet material at a given value of gas flow or pressure drop (PD), with account being taken of the following relationship between the parameters of flow and PD: