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:
Jan. 30, 1990
Filed:
Dec. 19, 1988
Applicant:
Inventors:
Tadeusz W Zerda, Fort Worth, TX (US);
Bruce Miller, Fort Worth, TX (US);
C A Quarles, Fort Worth, TX (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
2503581 ; 250308 ; 250393 ;
Abstract
A method is shown for measuring naturally occurring pores in a specimen material. A positron is emitted from a radioactive source and enters a material to pick up an electron to form positronium. The positronium decays very rapidly into two gamma rays. The lifetime of the positronium depends on the size of the pore it is trapped within. The larger the pore, the longer the positronium will last. By measuring the decay rate of positrons over an extended time scale in the range from 30 to 500 nsec., a near relation can be developed between positronium lifetime and pore diameter.