Environmental Test Systems, Inc.

Hach Company

Carol Ann Terry

Kenneth A Blake

Chauncey O Rupe

Kenneth Allen Blake

Chauncey Orvis Rupe

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.

Method and device for the determination of polymeric biguanides in

A test device and method of use for determination of aqueous halide ions is described. The device has a porous matrix containing a silver dichromate reagent that gives a colorimetric response in the presence of halide ions and a cationic substance that prevents the formation of silver oxide products. The cationic substance has no colorimetric response in the presence of halide ions that would interfere with the measurement of the colorimetric change of the silver dichromate reagent.

Growing community of inventors

Cassopolis, MI, United States of America

Carol Ann Terry