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:
Feb. 10, 1976
Filed:
Jan. 17, 1975
Ludwig Wolf, Jr, Barrington, IL (US);
David G Dominguez, Fox Lake, IL (US);
Baxter Laboratories, Inc., Deerfield, IL (US);
Abstract
Method and apparatus for testing a membrane strip for leaks due to pin holes are disclosed. A detector fluid is applied to one face of the strip while bringing a detection medium into proximity with the other face thereof, and producing a pressure difference between the opposite faces of the strip in a sense to cause flow of the detector fluid through any open pin holes in the strip, and accordingly into contact with the detection medium. In accordance with this invention, a membrane-compatible liquid is applied to the membrane strip prior to testing for pin holes, so that the liquid is retained in the pin holes by capillary attraction. Accordingly, the flow of detector fluid through pin holes which are less than a predetermined size is prevented. The predetermined size may be controlled by the magnitude of pressure difference between opposite faces and the nature of the membrane-compatible liquid. As a result, the presence only of holes larger than the predetermined size is detected.