Baxter Laboratories, Inc.

David G Dominguez

Ludwig Wolf, Jr

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.

Growing community of inventors

Fox Lake, IL, United States of America

David G Dominguez