Techniques for calculating gas concentrations in a fluid environment

1. A system comprising:

a sensing unit including:

a gas sensor configured to generate a gas sensor signal in response to a presence of at least one gas, and

a heater configured to adjust a temperature of the sensor; and

at least one processor adapted to:

control the heater to adjust the temperature of the sensor to a first temperature at a first time;

determine a first signal value by measuring the gas sensor signal at the first time;

control the heater to adjust the temperature of the sensor to a second temperature at a second time, wherein the first temperature and the second temperature are different;

determine a second signal value by measuring the gas sensor signal at the second time; and

calculate concentration information for the at least one gas based at least in part on:

the first signal value and a relationship between resistance of the gas sensor versus a concentration of H 2 when the gas sensor is at the first temperature; and

the second signal value and a relationship between resistance of the gas sensor versus a concentration of H 2 when the gas sensor is at the second temperature.

2. The system of claim 1 , wherein:

the gas sensor is configured to generate the gas sensor signal in response to a presence of a first gas and a second gas; and

the concentration information for the at least one gas includes concentration information for the first gas and does not substantially include concentration information for the second gas.

3. The system of claim 2 , wherein the first gas is H 2 and the second gas is O 2 .

4. The system of claim 1 , wherein the at least one processor is further adapted to:

control the heater to adjust the temperature of the sensor to a third temperature at a third time;

determine a third signal value by measuring the gas sensor signal at the third time; and

calculate concentration information for the at least one gas based at least in part on:

the first signal value and the first calibration relationship of the gas sensor at the first temperature;

the second signal value and the second calibration relationship of the gas sensor at the second temperature; and

the third signal value and a third calibration relationship of the gas sensor at the third temperature.

5. The system of claim 1 , further comprising:

an additional sensing unit including:

a gas sensor configured to generate an additional gas sensor signal in response to the presence of the at least one gas, and

a heater configured to adjust a temperature of the additional sensor; and

wherein the at least one processor is adapted to:

control the heater of the additional sensing unit to adjust the temperature of the additional gas sensor to an additional temperature at the first time and the second time;

determine a sequence of varying signal values by periodically measuring the additional gas sensor signal; and

determine concentration information for the at least one gas based at least in part on the first signal value, the second signal value, and the varying signal values.

6. The system of claim 5 , wherein the at least one processor is adapted to calibrate the gas sensor using the varying signal values.

7. The system of claim 5 , wherein the additional temperature and the first temperature are substantially the same.

8. The system of claim 1 , wherein:

the first signal value comprises a rate of change of the gas sensor signal at the first time; and

the second signal value comprises a rate of change of the gas sensor signal at the second time.

9. A method comprising:

exposing a gas sensor to at least one gas;

adjusting a temperature of the gas sensor to a first temperature at a first time;

determining a first signal value by measuring a gas sensor signal from the gas sensor at the first time;

adjusting the temperature of the gas sensor to a second temperature at a second time;

determining a second signal value by measuring the gas sensor signal at the second time;

calculating concentration information for the at least one gas based at least in part on:

the first signal value and a relationship between resistance of the gas sensor versus a concentration of H 2 when the gas sensor is at the first temperature; and

the second signal value and relationship between resistance of the gas sensor versus a concentration of H 2 when the gas sensor is at the second temperature; and

wherein the first temperature is different than the second temperature.

10. The method of claim 9 , wherein:

the gas sensor is configured to generate the gas sensor signal in response to a presence of a first gas and a second gas; and

the concentration information for the at least one gas includes concentration information for the first gas and does not substantially include concentration information for the second gas.

11. The method of claim 10 , wherein the first gas is H 2 and the second gas is O 2 .

12. The method of claim 9 , further comprising:

adjusting the temperature of the sensor to a third temperature at a third time;

determining a third signal value by measuring the gas sensor signal at the third time; and

wherein said calculating concentration information for at least one gas further comprises calculating concentration information for the at least one gas based at least in part on:

the first signal value and the first calibration relationship of the gas sensor at the first temperature;

the second signal value and the second calibration relationship of the gas sensor at the second temperature; and

the third signal value and a third calibration relationship of the gas sensor at the third temperature.

13. The method of claim 9 , further comprising:

controlling a heater associated with an additional gas sensor to adjust the temperature of the additional gas sensor to an additional temperature at the first time and the second time:

determining a sequence of varying signal values by periodically measuring an additional gas sensor signal of a gas sensor of the additional sensing unit; and

determining concentration information for the at least one gas based at least in part on the first signal value, the second signal value, and the varying signal values.

14. The method of claim 13 , further comprising:

calibrating the gas sensor using the varying signal values.

15. The method of claim 13 , wherein the additional temperature and the first temperature are substantially the same.

16. The method of claim 9 , wherein:

the first signal value comprises a rate of change of the gas sensor signal at the first time; and

the second signal value comprises a rate of change of the gas sensor signal at the second time.

17. A method comprising:

creating, at a first time, a first state for a target environment, the target environment including the presence of at least one gas;

measuring, at the first time, a signal of a gas sensor in the target environment to determine a first value of the signal;

creating, at a second time, a second state for the target environment;

measuring, at the second time, the signal of the gas sensor to determine a second value of the signal;

calculating concentration information for the at least one gas in the target environment based at least in part on the first value and the second value of the signal; and

wherein:

the first state is different than the second state;

the first state includes at least one of a first pressure of the target environment or a first bias voltage of the gas sensor; and

the second state includes at least one of a second pressure of the target environment or a second bias voltage of the gas sensor.

18. The method of claim 17 , wherein:

the first state comprises the first pressure of the target environment; and

the second state comprises the second pressure of the target environment.

19. The method of claim 17 , wherein:

the first state comprises the first bias voltage of the gas sensor; and

the second state comprises the second bias voltage of the gas sensor.

20. The method of claim 17 , wherein said calculating concentration information for at least one gas in the target environment based at least in part on the first value and the second value of the signal further comprises:

calculating concentration information for the at least one gas in the target environment based at least in part on the first value of the signal, the second value of the signal, and a plurality of calibration relationships of the gas sensor at the first state and the second state.

21. The method of claim 17 , further comprising:

generating the signal of the gas sensor in response to a presence of a first gas and a second gas; and

wherein the concentration information for the at least one gas includes concentration information for the first gas and does not substantially include concentration information for the second gas.

22. The method of claim 21 , wherein the first gas is H 2 and the second gas is O 2 .

23. The method of claim 17 , further comprising:

creating, at a third time, a third state for the target environment;

measuring, at the third time, the signal of the gas sensor to determine a third value of the signal; and

calculating concentration information for at least one gas in the target environment based at least in part on the first value of the signal, the second value of the signal, and the third value of the signal.

24. The method of claim 17 , wherein:

the a first value of the signal comprises a rate of change of the signal of the gas sensor at the first time; and

the a second value of the signal comprises a rate of change of the signal of the gas sensor at the second time.