Method for determining the amount of chlorine and bromine in water

• US 6,740,225 B2
• Filed: 03/06/2001
• Issued: 05/25/2004
• Est. Priority Date: 03/07/2000
• Status: Expired due to Fees

• Current Assignee: Hathaway Brown School
• Original Assignee: Hathaway Brown School
• Inventors: Liu, Chung-Chiun, Dudik, Laurie, Gurry, Bonnie, Shao, Meijun
• Primary Examiner(s): Noguerola, Alex
• Application Number:
  US09/799,969
• Publication Number:
  US 20010042692A1
• Time in Patent Office: 1,176 Days
• Field of Search: 204/400, 204/416, 204/431, 205/778.5, 205/779, 205/779.5
• US Class Current: 205/778.5
• CPC Class Codes: G01N 27/4045 for gases other than oxygen
• CPC Class Codes: G01N 33/182 specific anions in water electrochemical analysis G01N27/26; detection of ions by colorimetry G01N31/22

Abstract

A thick film electrochemical microsensor device for measuring or regulating chlorine and bromine in water, comprising a substrate to which is applied an optimum arrangement of at least two electrodes. The device is especially useful for measuring or regulating chlorine and bromine levels in swimming pool or spa water. A method of measuring or regulating ions of at least one of chlorine and bromine in water is also described, which comprises contacting the water with the microsensor of the present invention; measuring the current output of the microsensor; determining the level of at least one of chlorine and bromine indicated by the current output; and generating a signal.

Claims

1. A method of measuring or regulating ions of at least one of chlorine and bromine in water comprising:

contacting the water with a first electrochemical microsensor device comprising, a substrate supporting an arrangement of at least two electrodes, wherein one of the electrodes is an anode and one of the electrodes is a cathode, wherein the electrodes are formed using a thick film technique wherein the anode and the cathode are disposed adjacent to each other, and one said electrode is substantially nested within the other said electrode substantially within the same plane, and wherein the anode is adapted for oxidation of ions of said at least one of chlorine and bromine;

measuring the current output of the first microsensor;

determining the level of said at least one of chlorine and bromine indicated by the current output; and

generating a signal.

2. The method of claim 1, further comprising transmitting the signal to at least one device selected from the group consisting of display devices, recording means, alarm devices, and regulating means.

3. The method of claim 2, wherein the regulating means comprises a chlorine or bromine dispensing means.

4. The method of claim 1, wherein said step of determining the level of said at least one of chlorine and bromine indicated by the current output comprises:

generating a first signal based on the current output of the first microsensor;

providing a second microsensor substantially identical to the first microsensor, wherein the second microsensor is adapted to detect interference from chemical species other than chlorine and bromine;

contacting the water with the second microsensor;

measuring the current output of the second microsensor;

generating a second signal based on the current output of the second microsensor; and

subtracting the second signal from the first signal.

5. The method of claim 1 wherein the substrate is an insulating material selected from the group consisting of plastic, glass, ceramic, quartz, and mixtures thereof.

6. The method of claim 1, wherein the substrate is alumina.

7. The method of claim 1, wherein the anode comprises a material selected from the group consisting of gold, platinum, palladium, silver, and carbon.

8. The method of claim 1, wherein the cathode comprises a material selected from the group consisting of silver-silver chloride and mercury-mercuric chloride.

9. The method of claim 1, wherein said electrodes each comprises a connect portion and a sensing portion, wherein said connect portion of each electrodes connects the electrode to an electrical circuit, and is protected from the environment by an insulator, and wherein said sensing portion of each electrode is exposed to the environment.

10. The method of claim 1, wherein the thick film technique comprises:

providing at least one template containing a pattern for the arrangement of the electrodes;

contacting the substrate with the template;

applying at least one electrode precursor ink, and insulator precursor ink onto the template/substrate to form a sensor configuration according to the template pattern;

drying the sensor configuration; and

firing the sensor configuration.

11. The method of claim 1, wherein a first of said electrodes is rounded and a second of said electrodes has a concentric arm design, and wherein the first said electrode is disposed within the concentric arm of the second said electrode.

12. The method of claim 1, wherein a first of said electrodes and a second of said electrodes each have a square arm shape and the first said electrode is disposed within and surrounded on three sides by the second said electrode.