Multi-element smart gas sensor

• US 7,366,624 B2
• Filed: 06/06/2005
• Issued: 04/29/2008
• Est. Priority Date: 06/04/2004
• Status: Expired due to Fees

• Current Assignee: Esensors Inc.
• Original Assignee: Esensors Inc.
• Inventors: Wobschall, Darold
• Primary Examiner(s): Wachsman; Hal
• Assistant Examiner(s): O MALLEY, MARY CATHERINE
• Application Number:
  US11/145,858
• Publication Number:
  US 20050280408A1
• Time in Patent Office: 1,058 Days
• Field of Search: 702/91, 702/104, 73 102- 104, 73/10.6, 738/659
• US Class Current: 702/91
• CPC Class Codes: G01D 3/022 having an ideal characteristic, map or correction data stored in a digital memory
• CPC Class Codes: G01N 27/122 Circuits particularly adapted therefor, e.g. linearising circuits

Abstract

An electronic gas sensor signal conditioner which can automatically adapt to a wide variety of commercial off-the-shelf sensors and provide a digital output in a standard, easily used format. The signal conditioner has analog and digital sections. The analog section includes a sensor excitation sub-section and a signal amplification sub-section. The digital section comprises a microcontroller and controls the analog section. The digital section also converts the signal from the analog section into digital form, reads the sensor TEDS (Transducer Electronic Data Sheet), applies calibration constants and converts the signal into a standard, easily readable digital format.

Claims

1. A signal conditioner for an electronic gas sensor comprising a sensor element and sensor specification information stored in digital form therewith, the signal conditioner comprising:

a) an analog section for connection to the sensor element; and

b) a digital section for connection to the stored sensor specification information and connected in controlling relation to the analog section;

c) wherein the analog section includes a sensor excitation sub-section and a signal amplification sub-section;

d) wherein the sensor excitation sub-section comprises;

i) a switching regulator in the form of a dc-to-dc supply; and

ii) a digital potentiometer for providing feedback to the switching regulator in response to input from the digital section; and

e) so that the signal conditioner automatically adapts to a plurality of different electronic gas sensors and provides a digital output in a usable format.

2. The signal conditioner according to claim 1, wherein the sensor excitation sub-section comprises:

a) a precision voltage reference; and

b) a digitally controlled attenuation through which voltage from the reference is passed.

3. The signal conditioner according to claim 1, wherein the signal amplification sub-section comprises an amplifier having a low input bias current and a low input offset voltage.

4. The signal conditioner according to claim 1, wherein the digital section includes a microcontroller.

5. The signal conditioner according to claim 4, wherein the microcontroller has an analog-to-digital converter and provides a serial digital signal to the analog section.

6. The signal conditioner according to claim 1, wherein the digital section includes a microcontroller for reading the stored sensor specification information and for reconfiguring the analog section so that the signal conditioner matches the sensor specification information.

7. A signal conditioner for an electronic gas sensor comprising a sensor element and sensor specification information stored in digital form therewith, the signal conditioner comprising:

a) an analog section for connection to the sensor element, the analog section including a sensor excitation sub-section and a signal amplification sub-section; and

b) a digital section for connection to the stored sensor specification information and connected in controlling relation to the analog section, the digital section including a microcontroller for reading the stored sensor specification information and for reconfiguring the sensor excitation and signal amplification sub-sections for matching the signal conditioner to the sensor specification information;

c) wherein the sensor excitation sub-section comprises;

i) a switching regulator in the form of a dc-to-dc supply; and

ii) a digital potentiometer for providing feedback to the switching regulator in response to input from the digital section;

d) so that the signal conditioner automatically adapts to a plurality of different electronic gas sensors and provides a digital output in a usable form.

8. The signal conditioner according to claim 7, wherein the sensor excitation sub-section comprises:

a) a precision voltage reference; and

b) a digitally controlled attenuation through which voltage from the reference is passed.

9. The signal conditioner according to claim 7, wherein the signal amplification sub-section comprises an amplifier having a low input bias current and a low input offset voltage.

10. An electronic gas sensor system comprising:

a) an electronic gas sensor in the form of a plug-in module containing a sensor element and sensor specification information stored in digital form; and

b) a signal conditioner comprising an analog section for connection to the sensor element, the analog section including a sensor excitation sub-section and a signal amplification sub-section and a digital section for connection to the stored sensor specification information and connected in controlling relation to the analog section, the digital section including a microcontroller for reading the stored sensor specification information and for reconfiguring the sensor excitation and signal amplification sub-sections for matching the signal conditioner to the sensor specification information;

c) wherein the sensor excitation sub-section comprises;

i) a switching regulator in the form of a dc-to-dc supply; and

ii) a digital potentiometer for providing feedback to the switching regulator in response to input from the digital section;

d) so that the plug-in module can be removed and replaced by another plug-in module containing a different sensor element and the signal conditioner automatically adapts to that another plug-in module and to a plurality of different electronic gas sensors and provides a digital output in a usable format.

11. The electronic gas sensor system according to claim 10, wherein the sensor excitation sub-section comprises:

a) a precision voltage reference; and

b) a digitally controlled attenuation through which voltage from the reference is passed.

12. The electronic gas sensor system according to claim 10, wherein the signal amplification sub-section comprises an amplifier having a low input bias current and a low input offset voltage.

13. A signal conditioning method for electronic gas sensors each comprising a sensor element, sensor specification information stored in digital form therewith, an analog section connected to the sensor element, wherein the analog section includes a sensor excitation subsection having a switching regulator in the form of a dc-to-dc supply, and a digital potentiometer, the method comprising:

a) reading the sensor specification information;

b) using the sensor specification information to establish sensor electrical parameters for signal conditioning applied to the sensor;

c) using the digital potentiometer to provide feedback to the switching regulator in response to input from the digital section;

d) reading data obtained from the sensor;

e) using the sensor specification information to calculate and calibrate the data read from the sensor; and

f) providing an output comprising data from the sensor in digital form.

14. The method according to claim 13, wherein a microcontroller is used to read the sensor specification information.

15. The method according to claim 13, wherein the sensor electrical parameters comprise sensor voltage, sensor current and sensor resistance.

16. The method according to claim 13, wherein the signal conditioning applied to the sensor comprises excitation and amplification.