DISPOSABLE COLORIMETRIC INDICATOR AND SAMPLING DEVICE FOR LIQUIDS

• US 3,620,676 A
• Filed: 02/20/1969
• Issued: 11/16/1971
• Est. Priority Date: 02/20/1969
• Status: Expired due to Term

• Current Assignee: Pymah Corp (3M Company)
• Original Assignee: N/A
• Primary Examiner(s): Morris O. Wolk
• Assistant Examiner(s): R. M. Reese
• Application Number:
  US04/800,887
• Time in Patent Office: 999 Days
• Field of Search: 23/253TP,253,259 206/43,56A,17.5 128/2R,231,132 116/114.19,114.20
• US Class Current: 422/405
• CPC Class Codes: B01L 3/505 flexible containers not provided for above

Abstract

A disposable colorimetric indicator and sampling device for liquids is formed by embossing a synthetic plastic sheet with a syringelike cavity and closing the cavity by adhering a plane synthetic plastic sheet over the cavity, the two sheets being either heat sealed or adhesively joined together on the margins around the cavity, the cavity having a tubular portion one end of which opens at the edge of the adhered sheets, and the other end of the cavity being enlarged to form a finger compressible enlargement. A coating of a colorimetric indicator composition, soluble in or reactive with the liquid to be tested, is provided, the liquid being drawn into the tubular cavity by first compressing the enlargement, and releasing the pressure to draw in a liquid sample to react with the colorimetric indicator coating.

Claims

2. The device defined in claim 1 in which said body comprises a plane backing sheet of plastic adhered to the plane margins around a figure embossed in a sheet of plastic, said figure consisting of a tubular cavity having an enlargement closing one end thereof, the open end of said tubular cavity being at one edge of said embossed sheet.

3. The device defined in claim 1 in which the said tubular cavity has a coating over at least part of its inside wall, said coating comprising an indicator reagent soluble in the liquid to be tested.

4. The device defined in claim 2 in which the said tubular cavity has a coating over at least part of its inside wall, said coating comprising an indicator reagent soluble in the liquid to be tested.

5. The device defined in claim 4, in which said partial coating on said tubular cavity wall is a stripe of flexographic ink comprising a colorimetric pH indicator.

6. The device claimed in claim 4 in which said partial coating on said tubular cavity wall is a stripe of flexographic ink comprising a free chlorine indicator.