Gas sensor and method for analyzing the measured variables

• US 20150192554A1
• Filed: 01/08/2015
• Published: 07/09/2015
• Est. Priority Date: 01/08/2014
• Status: Abandoned Application

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: KOOP, Paul, Schaefer, Frank
• Application Number:
  US14/592,151
• Publication Number:
  US 20150192554A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 33/004 for CO, CO2
• CPC Class Codes: G01N 33/0065 using more than one threshold
• CPC Class Codes: G01N 33/007 Arrangements to check the analyser calibrating G01N33/0006
• CPC Class Codes: G08B 21/14 Toxic gas alarms G08B21/16 takes precedence

Abstract

A method and an analysis unit for analyzing the measured variables of a gas sensor, and a gas sensor which is operated using this method, provides that the fundamental method detects measured variables of a gas sensor, which represent the concentration of the gas to be monitored. Subsequently, two analysis modes are provided in the method, which differ essentially due to the speed and precision of the measured variable analysis. In a first analysis mode, at least one measured variable and/or the difference between two successive measured variables is compared to a threshold value. Depending on the output of the comparison, subsequently a first gas concentration signal is generated or not. The situation is similar in the second analysis mode, an average value calculation of at least two measured variables being carried out here and a second gas concentration signal being generated as a function of the result.

Claims

1. A method for analyzing the measured variables of a gas sensor, the method comprising:

detecting measured variables of a gas sensor representing the concentration of the gas to be detected;

in a first analysis mode, as a function of a comparison of at least one measured variable and/or a difference between two successive measured variables to a first threshold value, generating a first gas concentration signal; and

in a second analysis mode, as a function of an average value calculation of at least two measured variables, generating a second gas concentration signal.

2. The method of claim 1, wherein in the first analysis mode, as a function of the overshoot of the first threshold value by the one measured variable and/or the difference between two successive measured variables, a safety-critical situation is recognized, and wherein at least one of a first warning signal and a control signal for initiating countermeasures is generated.

3. The method of claim 1, wherein in the second analysis mode, as a function of the second threshold value being exceeded by the second gas concentration signal, a comfort-critical situation is recognized, and wherein at least one of a second warning signal and a control signal for initiating comfort measures is generated.

4. The method of claim 1, wherein the gas sensor includes at least two detector channels, and wherein the measured variables for generating the first gas concentration signal are detected from a first detector channel and those for generating the second gas concentration signal are detected from a second detector channel.

5. The method of claim 4, wherein balancing of the measured variables of the first and the second detector channels is performed using the measured variables of a reference channel of the gas sensor.

10. The analysis unit of claim 4, wherein the analysis arrangement balances the measured variables of at least one of the first channel and the second detector channel using the measured variables of a reference channel of the gas sensor.

16. The method of claim 1, wherein the gas sensor includes a CO₂ gas sensor.

17. The method of claim 1, wherein the gas sensor includes a CO₂ gas sensor, and the gas detected includes CO₂.

6. An analysis unit for a gas sensor, comprising:

an analysis arrangement configured to analyze measured variables of the gas sensor, by performing the following;

detecting measured variables of a gas sensor representing the concentration of the gas to be detected;

in a first analysis mode, as a function of a comparison of at least one measured variable and/or a difference between two successive measured variables to a first threshold value, generating a first gas concentration signal; and

in a second analysis mode, as a function of an average value calculation of at least two measured variables, generating a second gas concentration signal.

7. The analysis unit of claim 6, wherein the analysis arrangement recognizes a safety-critical situation in the first analysis mode as a function of the first threshold value being exceeded by the one measured variable and/or the difference of two successive measured variables, and wherein the analysis arrangement generates at least one of a first warning signal and a control signal for initiating countermeasures.

8. The analysis unit of claim 6, wherein the analysis arrangement, in the second analysis mode, as a function of a second threshold value being exceeded by the second gas concentration signal, recognizes a comfort-critical situation, and wherein the analysis arrangement generates at least one of a second warning signal and a control signal for initiating comfort measures.

9. The analysis unit of claim 6, wherein the analysis arrangement detects the measured variables for generating the first gas concentration from a first detector channel of the gas sensor and detects those for generating the second gas concentration signal from a second detector channel of the gas sensor.

18. The analysis unit of claim 6, wherein the gas sensor includes a CO₂ gas sensor.

19. The analysis unit of claim 6, wherein the gas sensor includes a CO₂ gas sensor, and the gas detected includes CO₂.

11. A gas sensor, comprising:

an analysis unit for a gas sensor, including an analysis arrangement configured to analyze measured variables of the gas sensor, by performing the following;

detecting measured variables of a gas sensor representing the concentration of the gas to be detected;

in a first analysis mode, as a function of a comparison of at least one measured variable and/or a difference between two successive measured variables to a first threshold value, generating a first gas concentration signal; and

in a second analysis mode, as a function of an average value calculation of at least two measured variables, generating a second gas concentration signal.

12. The gas sensor of claim 11, wherein the gas sensor has at least two detector channels, in which measured variables are generated independently of one another, which represent the concentration of the gas to be detected.

13. The gas sensor of claim 12, wherein the gas sensor has a reference channel, with the aid of which measured variables are generated independently of the concentration of the gas to be detected.

14. The gas sensor of claim 12, wherein the gas sensor includes a CO₂ gas sensor.

15. The gas sensor of claim 12, wherein the gas sensor includes a CO₂ gas sensor, and the gas detected includes CO₂.