Electrochemical sensor compensated for relative humidity

• US 20050269203A1
• Filed: 08/05/2005
• Published: 12/08/2005
• Est. Priority Date: 10/22/2001
• Status: Active Grant

• Current Assignee: Perkinelmer Health Sciences Incorporated (Perkinelmer Incorporated)
• Original Assignee: Perkinelmer Las
• Inventors: Dalmia, Avinash, Prohaska, Otto J.
• Granted Patent: US 7,887,683 B2
• Time in Patent Office: Days
• US Class Current: 204/431
• 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 counter and reference electrode being deposited on said surface;

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 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; and

said second thickness being greater than said first thickness.

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

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

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

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

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

8. An electrochemical gas sensor comprising:

a first cell in communication with a second cell;

each cell having;

a substrate having a surface;

a counter and reference electrode being deposited on said surface;

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; and

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

9. The electrochemical gas sensor according to claim 8, wherein said first electrolytic material includes a first thickness.

10. The electrochemical gas sensor according to claim 8, wherein said second electrolytic material includes a second thickness and wherein said second thickness is greater than said first thickness.

11. The electrochemical gas sensor according to claim 8, wherein said first and said second sensing electrodes are the same material.

12. The electrochemical gas sensor according to claim 8, wherein said first and said second sensing electrodes are different materials.