Device for measuring the free chloride content of water

Patent metadata

Field	Value
Publication number	US-9513255-B2
Application number	US-201214234921-A
Country	US
Kind code	B2
Filing date	Jul 25, 2012
Priority date	Jul 25, 2011
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

An amperometric sensor circuit for measuring chlorine concentration in water. The circuit includes first and second working electrodes coated with a hydrophilic membrane. A power supply and biasing circuit is configured to deliver a generally constant voltage between the first working electrode and a reference electrode and to generally deliver a constant current between the second working electrode and a counter electrode. A measurement circuit measures the current between the counter electrode and the first working electrode. A processing circuit is provided for determining the chlorine concentration based on the current measured by the measurement circuit.

First claim

The invention claimed is:

1. Device for measuring the chlorine content of a water, said device comprising at least one amperometric sensor of chlorine comprising a reference electrode, a counter electrode, a first working electrode and a second working electrode, said reference electrode and said first working electrode being connected to a voltage generator for generating a difference in electric potential, said counter electrode and said first working electrode being connected to a current measuring device for measuring electric current, said counter electrode and said second working electrode being linked to a current generator for generating electric current, said device further comprising a membrane coating said first and second working electrodes, said membrane being in contact with said working electrodes and comprising a gel permeable to hypochlorous acid (HOCl) and to hypochlorite ions (OCl − ).

2. The device of claim 1 characterized in that said membrane is made of a polymer.

3. The device according to claim 2 characterized in that said polymer is Poly(2-hydroxyethyl methacrylate).

4. The device according to claim 1 characterized in that the device comprises a variable voltage generator for driving in order to implement or not implement said current generator.

5. The device according to claim 1 characterized in that the device comprises a second amperometric sensor of chlorine.

6. The device according to claim 5 characterized in that said first and second amperometric sensors of chlorine are identical.

7. The device according to claim 5 characterized in that said second amperometric sensor of chlorine comprises a second reference electrode, a second counter electrode and a single working electrode, said second reference electrode and second working electrode being connected to a second voltage generator for generating a difference in electric potential, said second working electrode and second counter electrode being connected to a second current measuring device for measuring current.

8. The device of claim 1 characterized in that the device comprises a variable voltage regulator for controlling the value of the intensity of the electric current delivered by said current generator.

9. The device according to claim 1 characterized in that said working electrodes assume the shape of disks.

10. The device according to claim 1 characterized in that said working electrodes assume the form of combs.

11. The amperometric sensor circuit of claim 1 , wherein the power supply and biasing circuit comprises a biopotentiostat.

12. The amperometric sensor circuit of claim 1 , wherein the power supply and biasing circuit comprises:
a first potentiostat configured to deliver the constant voltage between the first working electrode and the reference electrode; and
a separate, second potentiostat configured to deliver the constant current between the second working electrode and the counter electrode.

13. The amperometric sensor circuit of claim 1 , wherein the measurement circuit comprises a voltmeter or ammeter.

14. An amperometric sensor circuit operative to measure a chlorine concentration of water, comprising:
first and second working electrodes that are each coated with a respective hydrophilic membrane;
a power supply and biasing circuit configured to, based on a resistivity or conductivity of water in contact with the hydrophilic membranes, deliver a constant voltage between the first working electrode and a reference electrode, and to deliver a constant current between the second working electrode and a counter electrode;
a measurement circuit configured to measure a current between the counter electrode and the first working electrode; and
a processing circuit operatively connected to the measurement circuit, and configured to determine a chlorine concentration of the water based on the current measured by the measurement circuit.

Assignees

• Beriet Carine
• De Coulon Yves
• Lemoine Cyrille
• Veolia Water Solutions & Tech

Inventors

• Beriet Carine
• De Coulon Yves
• Lemoine Cyrille

Classifications

• G01N27/4168

  Oxidation-reduction potential, e.g. for chlorination of water (water analysis G01N33/18) · CPC title

• G01N27/49 Primary

  Systems involving the determination of the current at a single specific value, or small range of values, of applied voltage for producing selective measurement of one or more particular ionic species · CPC title

• G01N27/4045 Primary

  for gases other than oxygen · CPC title