Kenneth Steven Blake

US Patent:

54985471, Mar 12, 1996

Filed:

May 24, 1994

Appl. No.:

8/248296

Inventors:

Kenneth A. Blake - Elkhart IN
Chauncey O. Rupe - Elkhart IN
Carol A. Terry - Cassopolis MI

Assignee:

Environmental Test Systems, Inc. - Elkhart IN

International Classification:

G01N 3300

US Classification:

436111

Abstract:

A test method and device is described for determining biguanides in aqueous fluids such as swimming pool water which involve contacting the fluid with a matrix incorporating a pH sensitive indicator material which exhibits the biguanide error effect. A buffer is advantageously used to maintain the test system within a defined constant pH range to eliminate the effect of pH changes on the test system.

US Patent:

53307151, Jul 19, 1994

Filed:

Dec 30, 1992

Appl. No.:

7/998203

Inventors:

Kenneth A. Blake - Elkhart IN
James E. Christner - Elkhart IN
Leonard J. Lucchese - Elkhart IN

Assignee:

Environmental Test Systems, Inc. - Elkhart IN

International Classification:

G01N 2177

US Classification:

422 56

Abstract:

A unitized multilayer dry reagent analytical chemistry test structure and device and method of fabricating such device is described. The device includes two or more contiguous layers of absorbent or porous paper or polymeric material, at least one of which is incorporated with a test reagent composition, the layers attached to each other with intermediate porous attachment layers by fusion bonding. When the device is contacted with the fluid being tested the attachment layers allow the free flow of such fluid from one layer to the next.