Method of, and sensor for, testing liquids

• US 20020022934A1
• Filed: 07/23/2001
• Published: 02/21/2002
• Est. Priority Date: 07/21/2000
• Status: Active Grant

• Current Assignee: ABB Patent GmbH (ABB Limited)
• Original Assignee: ABB Patent GmbH (ABB Limited)
• Inventors: Keeping, Sean, Krippner, Peter, Binz, Dieter, Vogel, Albrecht
• Granted Patent: US 6,564,155 B2
• Time in Patent Office: Days
• US Class Current: 702/50
• CPC Class Codes: G01N 31/22 using chemical indicators G01N31/02 takes precedence
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/20 Oxygen containing

Abstract

A method and an apparatus tests liquids. When the method is implemented, following a reaction of constituents in the liquid with the maximum quantity at least of one free oxidizing agent and/or reagent contained in the liquid, the quantity of oxidizing agent and/or reagent remaining in the liquid is displayed visually as a measure of the quantity of constituents in the liquid reacting with the oxidizing agent and/or reagent. For implementing the method, use is made of a sensor that is configured as a sheet-like structural element and is provided with at least one inlet opening, a sample-accommodating channel, a mechanical pump, a transporting capillary, a detection zone, an emptying channel, and an outlet opening.

Claims

1. A method of monitoring liquids, which comprises:

sampling a liquid containing constituents;

dissolving a maximum amount of a reagent in the liquid;

reacting the reagent with the constituents to produce a remaining amount of the reagent;

visually detecting the remaining amount of the reagent; and

correlating the detected remaining amount of the reagent with a quantity of the constituents.

2. The method according to claim 1, wherein the reagent is an oxidizing reagent.

3. The method according to claim 1, which comprises, after reacting the reagent with the constituents, reacting the remaining amount of the reagent with a color indicator.

4. The method according to claim 3, wherein the color indicator has a threshold concentration and the remaining amount of reagent must exceed the threshold concentration to react.

5. The method according to claim 3, which comprises:

using free oxygen as the reagent; and

correlating the amount of remaining reagent to a biological oxygen demand of the liquid.

6. The method according to claim 3, which comprises:

using free oxygen as the reagent; and

correlating the amount of remaining reagent to a chemical oxygen demand of the liquid.

7. A sensor for monitoring liquids, comprising:

a sheet-like structural element with an inlet opening;

a sample-accommodating channel connected to said inlet opening;

a mechanical pump in said sample-accommodating channel;

a transporting capillary connected to said sample-accommodating channel;

a detection zone connected to said transporting capillary;

an emptying channel connected to said detection zone; and

an outlet opening connected to said emptying channel.

8. The sensor according to claim 7, for monitoring liquids by sampling a liquid containing constituents, dissolving a maximum amount of a reagent in the liquid, reacting said reagent with the constituents to produce a remaining amount of said reagent, visually detecting the remaining amount of said reagent, and correlating the detected remaining amount of said reagent with a quantity of the constituents.

9. The sensor according to claim 7, including:

cutouts with defined dimensions and an outside formed in said first surface of said structural element containing said inlet opening, said sample-accommodating channel, said mechanical pump, said transporting capillary, said detection zone, said emptying channel, and said outlet opening; and

an elastic, gas-permeable sheet material connected to said first surface of said structural element and at least partially closing off said cutouts on the outside.

10. The sensor according to claim 7, wherein:

said transporting capillary has a first end and a second end, connects to said sample-accommodating at said first end, meanders, and connects to said detection zone at said second end;

said transporting capillary has a central region and a base; and

a catalyst is applied in said central region to said base of said capillary.

11. The sensor according to claim 10, wherein said catalyst is an enzyme.

12. The sensor according to claim 7, wherein said detection zone is configured as a channel;

and

the sensor includes;

a reagent directly downstream of said inlet opening of said detection zone; and

following said reagent, a plurality of color indicators disposed at a defined distance apart from one another.

13. The sensor according to claim 7, wherein said structural element has a thickness between two and five millimeters, and a surface area between five and eight square centimeters.

14. A method of monitoring liquids, which comprises, following a reaction of constituents in a liquid with a maximum quantity at least of one free oxidizing agent and a reagent contained in the liquid, displaying visually the quantity of oxidizing agent and reagent remaining in the liquid a quantity of the constituents in the liquid reacting with the oxidizing agent and reagent.