Apparatus and method for in-situ calibration of a photoacoustic sensor

Patent metadata

Field	Value
Publication number	US-2020103376-A1
Application number	US-201916699993-A
Country	US
Kind code	A1
Filing date	Dec 2, 2019
Priority date	Sep 7, 2015
Publication date	Apr 2, 2020
Grant date	—

Abstract

An apparatus for in-situ calibration of a photoacoustic sensor is provided. The apparatus includes a light emitter to emit light along a transmission path to a gas and an acoustic sensor element configured to detect an acoustic signal emitted from the gas based on the received light. Furthermore, the apparatus includes a sensing unit configured to detect the light transmitted along the transmission path and to provide an output signal, and a calibration unit to receive the output signal from the sensing unit and to provide a calibration information based on the output signal received from the sensing unit.

First claim

What is claimed is:

1 . A microelectromechanical system, comprising:
a light emitter configured to emit light along a transmission path to a gas; an acoustic sensor element configured to detect an acoustic signal emitted from the gas based on received light and generate an output signal based on the detected acoustic signal; a radiation sensor configured to detect the light transmitted along the transmission path and to provide an information signal based on the detected light; and a calibration unit, comprising at least one processor, configured to receive the information signal from the radiation sensor and to provide calibration information based on the information signal, wherein the light emitter, the acoustic sensor element, the radiation sensor, and the calibration unit are formed in a common semiconductor substrate, and wherein the radiation sensor comprises a semiconductor sensor formed within the semiconductor substrate.

2 . An apparatus for in-situ calibration of a photoacoustic sensor, the apparatus comprising:
a calibration unit comprising at least one processor, configured to calculate calibration information, wherein a light emitter of the photoacoustic sensor is configured to emit an electromagnetic spectrum, wherein the photoacoustic sensor is configured to provide at least two measurement signals based on at least two electromagnetic spectra, wherein the calibration unit is configured to compare the at least two measurement signals to obtain the calibration information, and wherein the calibration unit is configured to apply the calibration information to the photoacoustic sensor to perform the in-situ calibration.

3 . The apparatus according to claim 2 , wherein the calibration unit is configured to apply the calibration information to an output signal of the photoacoustic sensor to perform the in-situ calibration.

4 . The apparatus according to claim 2 , wherein the calibration unit is configured to control an electric signal at the light emitter,
wherein the light emitter is configured to emit an electromagnetic spectrum based on the electric signal, and wherein the calibration unit is further configured to adjust the electric signal at the light emitter based on the calibration information to perform the in-situ calibration.

5 . The apparatus according to claim 2 , further comprising:
a processing unit, comprising as least one further processor, configured to calibrate a determination of a gas concentration in the photoacoustic sensor using the calibration information to perform the in-situ calibration, wherein the determination of the gas concentration is based on a further measurement signal of the photoacoustic sensor.

6 . The apparatus according to claim 2 , further comprising:
a processing unit, comprising as least one further processor, configured to process an output signal of the photoacoustic sensor based on the calibration information to obtain an adjusted output signal of the photoacoustic sensor.

7 . The apparatus according to claim 2 , wherein:
the calibration unit is configured to calculate a current ratio of a first one of the at least two measurement signals and a second one of the at least two measurement signals, the calibration unit is further configured to compare the current ratio to a target ratio, and the calibration unit is configured to adjust an electric power of the light emitter such that an absolute difference of the current ratio to the target ratio is reduced.

8 . A method for in-situ calibration of a photoacoustic sensor, the method comprising:
calculating a calibration information, wherein an IR emitter of the photoacoustic sensor is configured to emit an electromagnetic spectrum based on an electric signal, wherein the photoacoustic sensor is configured to provide at least two measurement signals based on at least two electromagnetic spectra; and comparing the at least two measurement signals to obtain calibration information; and applying the calibration information to the photoacoustic sensor to perform the in-situ calibration.

9 . The method of claim 8 , wherein applying the calibration information to the photoacoustic sensor includes applying the calibration information to an output signal of the photoacoustic sensor to perform the in-situ calibration.

10 . The method of claim 8 , further comprising:
controlling an electric signal at the IR emitter; emitting an electromagnetic spectrum from the IR emitter based on the electric signal; and adjusting the electric signal at the IR emitter based on the calibration information to perform the in-situ calibration.

11 . The method of claim 8 , further comprising:
calibrating a determination of a gas concentration in the photoacoustic sensor using the calibration information to perform the in-situ calibration, wherein the determination of the gas concentration is based on a further measurement signal of the photoacoustic sensor.

12 . The method of claim 8 , further comprising:
processing an output signal of the photoacoustic sensor based on the calibration information to obtain an adjusted output signal of the photoacoustic sensor.

13 . The method of claim 8 , further comprising:
calculating a current ratio of a first one of the at least two measurement signals and a second one of the at least two measurement signals; comparing the current ratio to a target ratio; and adjusting an electric power of the IR emitter such that an absolute difference of the current ratio to the target ratio is reduced.

Assignees

• Infineon Technologies Ag

Inventors

• Kolb Stefan
• Dehe Alfons
• Huber Jochen
• Jost Franz
• Theuss Horst
• Woellenstein Juergen

Classifications

• G01N2021/1704

  in gases · CPC title

• G01N29/2418

  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 title

• H05B47/10

  Controlling the light source · CPC title

• G01N21/3504

  for analysing gases, e.g. multi-gas analysis · CPC title

• G01N29/30 Primary

  Arrangements for calibrating or comparing, e.g. with standard objects · CPC title