Method for measuring concentrations of gas moieties in a gas mixture
In at least one embodiment, a method is described for measuring concentrations of gas moieties in a gas mixture. A mixed-potential gas sensor is exposed to a gas mixture in order to obtain a first and a second mixed-potential gas sensor output responses. The first output response and a second output response are deconvoluted to measure a first analyte gas concentration and a second analyte gas concentration. Some of the output responses may be used as inputs to a control system.
1. A method comprising:
while exposing a gas mixture to a mixed-potential gas sensor including an anode and a cathode, passing a first and second bias between the anode and the cathode to obtain respectively a first and second response differential between the same anode and the same cathode; and
deconvoluting the first and second response differentials to determine both first and second analyte gas concentrations.
2. The method of claim 1 , further comprising the step of:
inputting the first and second analyte gas concentrations into a control system.
3. The method of claim 1 , wherein the mixed-potential gas sensor further includes an electrolyte, a power source, and an electrical property measurement device.
4. The method of claim 1 , wherein the gas mixture includes nitric oxide and nitrogen dioxide.
5. The method of claim 1 further comprising providing a chamber configured to receive the gas mixture, wherein the anode and cathode are disposed within the chamber and in contact with the gas mixture.
6. The method of claim 1 , wherein the first and second biases are respectively first and second potentials.
7. The method of claim 6 , wherein the first and second response differentials are respectively first and second currents.
8. The method of claim 1 , wherein the first and second biases are respectively first and second currents.
9. The method of claim 8 , wherein the first and second response differentials are respectively first and second potentials.
10. The method of claim 1 , wherein the deconvoluting step includes using a non-transitory computer-readable device having an instruction set for solving a simultaneous equation system.
11. The method of claim 10 , wherein the using step includes inputting a matrix of transfer functions for the first analyte gas and the second analyte gas in the gas mixture into the computer-readable device.
12. The method of claim 10 , wherein the simultaneous equation system is
M=CX+C′Y+C″
N=DX+D′Y+D″
where M is the first mixed-potential gas sensor response differential, N is the second mixed-potential gas sensor response differential, C is a first transfer function of an electromotive force for the first analyte gas having a first reduction potential at the first bias, and C′ is a second transfer function of the electromotive force for the second analyte gas having a second reduction potential at the first bias, D is the first transfer function of the electromotive force for the first analyte gas having a first reduction potential at the second bias, and D′ is the second transfer function of the electromotive force for the second analyte gas having the second reduction potential at the second bias, X is the first analyte gas concentration, Y is the second analyte gas concentration, C″ is a first constant and D″ is a second constant.