Electrochemical sensor compensated for relative humidity

• US 6,955,750 B2
• Filed: 10/22/2001
• Issued: 10/18/2005
• Est. Priority Date: 10/22/2001
• Status: Expired due to Fees

• Current Assignee: PerkinElmer LAS, Inc. (Perkinelmer Incorporated)
• Original Assignee: Perkinelmer Instruments LLC (Revvity, Inc.)
• Inventors: Dalmia, Avinash, Prohaska, Otto J.
• Primary Examiner(s): Olsen, Kaj K.
• Application Number:
  US10/029,626
• Publication Number:
  US 20030075443A1
• Time in Patent Office: 1,457 Days
• Field of Search: 204421-429, 204/415
• 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 an 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 electrolytic material on the sensing electrode of the reference sensor and a film of 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 first cell in communication with a second cell;

each cell having;

a substrate having a surface;

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

an electrolytic material in contact with said sensing electrode and having a thickness;

an electrolytic film having a thickness and covering said sensing electrode for increasing a contact area between said film, said sensing electrode, and a gas to be detected;

said thickness of said electrolytic material is larger than said thickness of said electrolytic film;

a reservoir in contact with said electrolytic material on a side opposite of said substrate; and

a solution in said reservoir for hydrating said electrolytic material.

2. The electrochemical gas sensor according to claim 1, wherein said substrates of said first and second cells are in contact with one another.

3. The electrochemical gas sensor according to claim 1, wherein said first and second cells further include a reference electrode in contact with said electrolytic material and being spaced apart from said sensing and counter electrodes.

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

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

6. An electrochemical gas sensor, comprising:

a first cell in communication with a second cell;

each cell having;

a substrate having a surface;

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

an electrolytic material in contact with said sensing electrode and having a thickness;

an electrolytic film having a thickness and covering said sensing electrode for increasing a contact area between said film, said sensing electrode, and a gas to be detected;

said thickness of said electrolytic material is larger than said thickness of said electrolytic film;

a reservoir in contact with said electrolytic material on a side opposite of said substrate;

a solution in said reservoir for hydrating said electrolytic material; and

said sensing electrode of said first cell being of a material that is more sensitive to detecting a gas than a material of said sensing electrode of said second cell.

7. The electrochemical gas sensor according to claim 6, wherein said sensing electrode of said second cell includes a material inert to a gas.

8. The electrochemical gas sensor according to claim 6, wherein said sensing electrode includes gold.

9. The electrochemical gas sensor according to claim 6, wherein said first and second cells further include a reference electrode being spaced apart from said sensing and counter electrodes.