Devices, systems and methods for testing gas sensors and correcting gas sensor output
View Patent ↗A method of adjusting the output of an electrochemical sensor including a working electrode and a counter electrode, includes: electronically causing a current flow between the working electrode and the counter electrode via an electrolyte without introducing a test analyte to the electrochemical sensor; measuring a response of the sensor to the current demand resulting from the electronically generated current flow; and using the measured response to adjust the sensor output during sampling of an analyte gas.
1. A method of adjusting the output of an electrochemical sensor including a working electrode and a counter electrode, comprising:
electronically causing a current flow between the working electrode and the counter electrode via an electrolyte independent of the presence of a test gas;
measuring a response of the sensor to the current demand resulting from the electronically generated current flow; and
applying an algorithm comprising a correction factor based upon the measured response to correct the sensor output during sampling of an analyte gas to compensate for changes in sensitivity of the sensor over time.
2. The method of claim 1 wherein a constant current is caused to flow between the working electrode and the counter electrode and the measured response is a potential difference.
3. The method of claim 1 wherein a constant potential difference is maintained between the working electrode and the counter electrode and the measured response is current.
4. The method of claim 1 wherein the electrochemical sensor further comprises a reference electrode.
5. The method of claim 1 wherein the electrolyte is a liquid electrolyte.
6. The method of claim 5 wherein the electrolyte is an aqueous electrolyte or an organic electrolyte.
7. The method of claim 1 wherein the electrolyte is a quasi-solid electrolyte.
8. The method of claim 7 wherein the quasi-solid electrolyte comprises a liquid ionic conductor immobilized by a high-surface-area, high-pore-volume solid.
9. The method of claim 1 wherein the electrolyte is a solid ionic conductor.
10. A sensor comprising:
a working electrode;
a counter electrode;
an electrolyte;
a power source in electrical connection with the working electrode and the counter electrode to electronically cause a current flow between the working electrode and the counter electrode of the presence of a test gas;
circuitry to measure a response of the sensor to the electronically generated current flow; and
an output system which corrects the output of the sensor during sampling of an analyte gas as a function of the measured response of the sensor to the electronically generated current flow to compensate for changes in sensitivity of the sensor over time.
11. The sensor of claim 10 wherein a constant current is caused to flow between the working electrode and the counter electrode and the measured response is a potential difference.
12. The sensor of claim 10 wherein a constant potential difference is maintained across the working electrode and the counter electrode and the measured response is current.
13. The sensor of claim 10 wherein the electrochemical sensor further comprises a reference electrode.
14. The sensor of claim 10 wherein the electrolyte is a liquid electrolyte.
15. The sensor of claim 14 wherein the electrolyte is an aqueous electrolyte or an organic electrolyte.
16. The sensor of claim 10 wherein the electrolyte is a quasi-solid electrolyte.
17. The sensor of claim 16 wherein the quasi-solid electrolyte comprises a liquid ionic conductor immobilized by a high-surface-area, high-pore-volume solid.
18. The sensor of claim 10 wherein the electrolyte is a solid ionic conductor.
19. The sensor of claim 10 wherein the output system includes an adjustment algorithm to correct the output of the sensor.