Claims
- 1. A sensor for measuring partial hydrogen pressure in a gas stream, comprising:a housing; a sensing element comprising first and second gas diffusing electrodes spaced from one another and disposed in said housing; a fuel-cell spacer having an acidic electrolyte disposed between said first and second electrodes; a first gas permeable membrane separating said first electrode from the gas stream and enabling hydrogen diffusion therethrough for contact with said first electrode, said first membrane being spaced from said first electrode by a first cavity enabling hydrogen diffused through said first membrane to contact said first electrode; a second gas permeable membrane separating said second electrode from atmospheric air and defining a second cavity therewith isolated from said first cavity; a seal precluding contact between hydrogen in the first cavity and the second electrode; and means for maintaining a hydrogen partial pressure gradient between said first electrode and an external gas stream containing hydrogen.
- 2. The sensor of claim 1, wherein said first membrane has higher permeability to hydrogen and lower permeability to gases with molecular dimensions greater than that of hydrogen.
- 3. The sensor of claim 1, wherein oxygen rate of permeation through said second membrane is higher than hydrogen rate of permeation through said first membrane, whereby oxygen furnished at said second electrode exceeds stochiometric oxygen necessary for the reaction with hydrogen.
- 4. The sensor of claim 1, wherein said first and second electrodes are connected through a load resistance to measure the sensor output.
- 5. The sensor of claim 1, wherein said first and second membranes are made of a polymeric material.
- 6. The sensor of claim 1, wherein said first and second electrodes are identical.
- 7. The sensor of claim 1 including a cover member for said housing having a connector for providing an electrical connection to said sensors and a third gas permeable membrane disposed in one of said cover member and said housing for receiving atmospheric air.
- 8. The sensor of claim 7, further comprises means for sealingly attaching the housing to an assembly carrying a gas stream.
- 9. The sensor of claim 7 wherein said second membrane enables natural diffusion of oxygen from atmospheric air.
- 10. The sensor of claim 7, wherein said first membrane is selected to have higher permeability to hydrogen and lower permeability to gases with molecular dimensions greater than that of hydrogen.
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/185,497, filed Feb. 28, 2000, the intire content of which is hereby incorporated by reference in this application.
US Referenced Citations (7)
Number |
Name |
Date |
Kind |
3852169 |
Kring et al. |
Dec 1974 |
A |
3966579 |
Chang et al. |
Jun 1976 |
A |
4051006 |
Neti et al. |
Sep 1977 |
A |
4271474 |
Belanger et al. |
Jun 1981 |
A |
4293399 |
Belanger et al. |
Oct 1981 |
A |
5200044 |
Milstein et al. |
Apr 1993 |
A |
5667653 |
Schneider et al. |
Sep 1997 |
A |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/185497 |
Feb 2000 |
US |