Electrochemical sensor compensated for relative humidity

• US 7,887,683 B2
• Filed: 08/05/2005
• Issued: 02/15/2011
• Est. Priority Date: 10/22/2001
• Status: Expired due to Fees

• Current Assignee: PerkinElmer Health Sciences, Inc. (Revvity, Inc.)
• Original Assignee: PerkinElmer Health Sciences, Inc. (Revvity, Inc.)
• Inventors: Prohaska, Otto J., Dalmia, Avinash
• Primary Examiner(s): Olsen; Kaj K
• Application Number:
  US11/198,812
• Publication Number:
  US 20050269203A1
• Time in Patent Office: 2,020 Days
• Field of Search: 204/415, 204421-429
• US Class Current: 204/424
• CPC Class Codes: G01N 27/4045 for gases other than oxygen
• CPC Class Codes: G01N 27/4071 using sensor elements of laminated structure
• CPC Class Codes: G01N 27/4074 for detection of gases other than oxygen

Abstract

The invention relates to an electrochemical gas sensor having both a reference sensor and an active sensor, whereby each reference and active sensor includes a substrate, a counter electrode deposited on a surface of the substrate, a sensing electrode also deposited on the surface, and a solid electrolytic material in electrical contact with both electrodes for carrying a flow of ions between them, which measures a concentration of a gas and compensates for relative humidity differences between sample gas and surrounding atmosphere. The sensor also includes a layer of solid electrolytic material on the sensing electrode of the reference sensor and a film of solid electrolytic material on the sensing electrode of the active sensor, whereby the layer is thicker than the film. The invention may further include a reference electrode in both the reference and active sensors for improving sensor accuracy and/or repeatability.

Claims

1. An electrochemical gas sensor comprising:

a substrate having a surface;

a reference sensor having a first counter electrode, first sensing electrode, and first reference electrode deposited on said surface;

an active sensor having a second counter electrode, second sensing electrode, and second reference electrode deposited on said surface, said reference sensor and said active sensor being spaced apart from one another;

a first electrolytic material having a first thickness and being in contact with said first sensing electrode for carrying a flow of ions;

a second electrolytic material having a second thickness and being in contact with said second sensing electrode for carrying a flow of ions, said second thickness being less than said first thickness; and

additional electrolytic material in contact with active sensor and reference sensor, wherein said additional electrolytic material acts as a conductive medium to carry ions from the active sensor to the reference sensor.

2. The electrochemical gas sensor of claim 1, wherein said first and said second sensing electrodes are the same material.

3. The electrochemical gas sensor of claim 1, wherein said first and said second sensing electrodes are different materials.

4. The electrochemical gas sensor of claim 1, wherein said first sensing electrode includes a material inert to a gas.

5. The electrochemical gas sensor of claim 1, wherein said first sensing electrode includes gold.

6. The electrochemical gas sensor of claim 1, further comprising a reservoir in contact with said first electrolytic material on a side opposite of said substrate.

7. The electrochemical gas sensor of claim 6, further comprising a solution in said reservoir for hydrating said electrolytic material.

8. The electrochemical gas sensor of claim 1, wherein the first electrolytic material is between 10 and 60 micrometers thick.

9. The electrochemical gas sensor of claim 1, further comprising a solution for wetting the first electrolytic material and the second electrolytic material.

10. The electrochemical gas sensor of claim 1, wherein the second electrolytic material is between 2.5 and 30 micrometers thick.

11. The electrochemical gas sensor of claim 1, wherein the thickness of said additional electrolytic material is greater than the thickness of both the first electrolytic material and second electrolytic material.

12. The electrolytic gas sensor of claim 1, wherein the thickness of the additional electrolytic material is approximately between 0.0002 and 0.04 inches thick.

13. An electrochemical gas sensor comprising:

a first cell in communication with a second cell;

each cell having;

a substrate having a surface;

an electrode being deposited on said surface, said electrode being both a counter and reference electrode;

a first sensing electrode and a second sensing electrode, being spaced apart from one another and from said counter and reference electrode, being deposited on said surface;

a first electrolytic material in contact with said first sensing electrode for carrying a flow of ions;

a second electrolytic material in contact with said second sensing electrode for carrying a flow of ions; and

additional electrolytic material in contact with the first sensing electrode and the second sensing electrode, wherein the additional electrolytic material acts as a conductive medium to carry ions from the second sensing electrode to the first sensing electrode.

14. The electrochemical gas sensor of claim 13, wherein said first electrolytic material includes a first thickness.

15. The electrochemical gas sensor of claim 13, wherein said first electrolytic material includes a first thickness and said second electrolytic material includes a second thickness, said second thickness being less than said first thickness.

16. The electrochemical gas sensor of claim 13, wherein said first and said second sensing electrodes are the same material.

17. The electrochemical gas sensor of claim 13, wherein said first and said second sensing electrodes are different materials.

18. The electrochemical gas sensor of claim 13, further comprising a reservoir in contact with said first electrolytic material on a side opposite of said substrate.

19. An electrochemical gas sensor comprising:

a substrate having a surface;

three electrodes, said electrodes comprising a counter/reference electrode, a first sensing electrode and a second sensing electrode, said counter/reference electrode, said first sensing electrode and said second sensing electrode being spaced apart from one another and deposited on said surface of said substrate;

a first electrolytic material having a first thickness and being in contact with said first sensing electrode for carrying a flow of ions;

a second electrolytic material having a second thickness and being in contact with said second sensing electrode for carrying a flow of ions, said second thickness being less than said first thickness; and

additional electrolytic material in contact with the three electrodes, wherein the additional electrolytic material acts as a conductive medium to carry ions from the second sensing electrode to the first sensing electrode.

20. The electrochemical gas sensor of claim 19, further comprising a reservoir in contact with said first electrolytic material on a side opposite of said substrate.

21. The electrochemical gas sensor of claim 19, further comprising a solution in said reservoir for hydrating said electrolytic material.