PHOTOACOUSTIC GAS SENSOR DEVICE AND A METHOD FOR ANALYZING GAS

• US 20150101395A1
• Filed: 10/14/2013
• Published: 04/16/2015
• Est. Priority Date: 10/14/2013
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Dehe, Alfons, Kolb, Stefan, Theuss, Horst
• Granted Patent: US 9,513,261 B2
• Time in Patent Office: Days
• US Class Current: 73/24.02
• CPC Class Codes: G01N 2021/1704 in gases
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 2291/021 Gases
• CPC Class Codes: G01N 29/2418 using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046
• CPC Class Codes: G01N 29/2425 optoacoustic fluid cells therefor
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects

Abstract

A photoacoustic gas sensor device for analyzing gas includes an emitter module and a pressure-sensitive module. The emitter module is arranged on a carrier substrate and emits light pulses. The pressure-sensitive module is arranged on the carrier substrate within a reference gas volume. The reference gas volume is separated from a volume intended to be filled with a gas to be analyzed. Further, the pressure-sensitive module generates a sensor signal indicating information on an acoustic wave caused by light pulses emitted by the emitter module interacting with a reference gas within the reference gas volume. Additionally, the emitter module is arranged so that light pulses emitted by the emitter module reach the reference gas volume after crossing the volume intended to be filled with the gas to be analyzed.

Claims

1. A photoacoustic gas sensor device for analyzing gas comprising:

an emitter module arranged on a carrier substrate and configured to emit light pulses; and

a pressure sensitive module arranged on the carrier substrate within a reference gas volume, wherein the reference gas volume is separated from a volume intended to be filled with a gas to be analyzed, wherein the pressure sensitive module is configured to generate a sensor signal indicating information on an acoustic wave caused by light pulses emitted by the emitter module interacting with a reference gas within the reference gas volume,

wherein the emitter module is arranged so that light pulses emitted by the emitter module reach the reference gas volume after crossing the volume intended to be filled with the gas to be analyzed.

2. The photoacoustic gas sensor device according to claim 1, comprising an analyzing module configured to determine information on the gas to be analyzed based on the sensor signal.

3. The photoacoustic gas sensor device according to claim 2, wherein the analyzing module is arranged on the carrier substrate and implemented on a semiconductor die different from a semiconductor die comprising the pressure sensitive module.

4. The photoacoustic gas sensor device according to claim 1, wherein the pressure sensitive module and the emitter module are implemented on different semiconductor dies.

5. The photoacoustic gas sensor device according to claim 1, wherein the pressure sensitive module comprises at least a membrane configured to be moved by the acoustic wave caused by light pulses emitted by the emitter module interacting with a reference gas within the reference gas volume.

6. The photoacoustic gas sensor device according to claim 5, wherein the membrane is arranged so that a reference gas within the reference gas volume surrounds the membrane during analyzing gas, wherein the emitter module and the pressure sensitive module are arranged so that at least a volume located at one side of the membrane cannot be reached by light pulses emitted by the emitter module or less than 1% of the light pulses emitted by the emitter module is able to reach the volume located at the one side of the membrane.

7. The photoacoustic gas sensor device according to claim 1, wherein the emitter module is arranged so that light emitted by the emitter module reaches the reference gas volume after only crossing the volume intended to be filled with the gas to be analyzed.

8. The photoacoustic gas sensor device according to claim 1, comprising a second reference gas volume separated from the first reference gas volume and the volume intended to be filled with a gas to be analyzed.

9. The photoacoustic gas sensor device according to claim 8, wherein the emitter module is arranged so that light pulses emitted by the emitter module reach the second reference gas volume after crossing the volume intended to be filled with the gas to be analyzed and after crossing the first reference gas volume.

10. The photoacoustic gas sensor device according to claim 8, comprising a second pressure sensitive module arranged on the carrier substrate within the second reference gas volume.

11. The photoacoustic gas sensor device according to claim 8, comprising a second emitter module arranged on the carrier substrate and configured to emit light pulses, wherein the second emitter module is arranged so that light pulses emitted by the second emitter module reach the second reference gas volume after crossing the volume intended to be filled with the gas to be analyzed.

12. The photoacoustic gas sensor device according to claim 1, wherein the emitter module is configured to emit infrared light pulses.

13. The photoacoustic gas sensor device according to claim 1, wherein the carrier substrate comprises a basically flat geometry or comprises at least a part with a cross section comprising a U-shaped geometry or an L-shaped geometry.

14. The photoacoustic gas sensor device according to claim 13, wherein the emitter module and the pressure sensitive module are arranged on the same side or at opposite sides of the carrier substrate comprising a basically flat geometry.

15. The photoacoustic gas sensor device according to claim 13, wherein the emitter module is arranged at a first leg of the L-shaped or U-shaped geometry of the carrier substrate and the pressure sensitive module is arranged at a second leg of the L-shaped or U-shaped geometry of the carrier substrate.

16. The photoacoustic gas sensor device according to claim 13, wherein the emitter module is arranged within the volume intended to be filled with the gas to be analyzed.

17. The photoacoustic gas sensor device according to claim 1, wherein the emitter module is configured to emit first light pulses within a first frequency range and with a first temporal occurrence characteristic and second light pulses within a second frequency range and with a second temporal occurrence characteristic, wherein the pressure sensitive module is configured to generate the sensor signal indicating information on first acoustic waves caused by the first light pulses emitted by the emitter module interacting with a reference gas and second acoustic waves caused by the second light pulses emitted by the emitter module interacting with a reference gas.

18. A photoacoustic gas sensor device for analyzing gas comprising:

an emitter module arranged on a carrier substrate and configured to emit first light pulses within a first frequency range and with a first temporal occurrence characteristic and second light pulses within a second frequency range and with a second temporal occurrence characteristic; and

a pressure sensitive module arranged on the carrier substrate, wherein the pressure sensitive module is configured to generate a sensor signal indicating information on first acoustic waves caused by the first light pulses emitted by the emitter module interacting with a gas to be analyzed and second acoustic waves caused by the second light pulses emitted by the emitter module interacting with the gas to be analyzed.

19. The photoacoustic gas sensor device according to claim 18, wherein the emitter module is configured to emit the first light pulses with a time distance of less than 20 ms representing the first temporal occurrence characteristic and the second light pulses with a time distance of more than 20 ms representing the second temporal occurrence characteristic.

20. A method for analyzing gas comprising:

emitting light pulses by an emitter module arranged on a carrier substrate, wherein the emitted light pulses reach a reference gas volume after crossing a volume intended to be filled with the gas to be analyzed, wherein the reference gas volume is separated from the volume intended to be filled with the gas to be analyzed; and

generating a sensor signal by a pressure sensitive module arranged on the carrier substrate within the reference gas volume, wherein the sensor signal indicates information on an acoustic wave caused by the emitted light pulses interacting with a reference gas within the reference gas volume.