Optical gas sensor comprising an LED emitter for the emission of light of a narrow bandwidth

• US 10,190,974 B2
• Filed: 11/02/2015
• Issued: 01/29/2019
• Est. Priority Date: 11/10/2014
• Status: Active Grant

• Current Assignee: Draeger Safety Incorporated (Dragerwerk AG)
• Original Assignee: Draeger Safety Incorporated (Dragerwerk AG)
• Inventors: Pape, Andre, Trollsch, Arne
• Primary Examiner(s): Nguyen, Sang H
• Application Number:
  US15/525,338
• Publication Number:
  US 20170322149A1
• Time in Patent Office: 1,184 Days
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 21/31 Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis

Abstract

An optical gas sensor (1), for quantitatively measuring a concentration of one or more gases, includes a radiation source (2) for emitting light waves (L), a cuvette (3) for holding a gas (G) to be measured, and a detector (4) for measuring light intensities. The light source (2) includes at least one emitter (5) of light waves (L) and is configured to emit light waves (L) of at least one first wavelength and of a second wavelength different from the first wavelength simultaneously or separately from each other. The emitter (5) is further configured to emit a spectrum the full half-life width of which is a maximum 50% of the effective wavelength, and to emit light waves (L) having a controlled beam path. The detector (4) is configured to quantitatively detect an intensity of emitted light waves (L) of the first wavelength and of the second wavelength.

Claims

1. An optical gas sensor for quantitatively measuring the concentration of one or more gases, the optical gas sensor comprising:

a radiation source for emitting light waves;

a cuvette for holding a gas to be measured; and

a detector for measuring light intensities, wherein;

the radiation source comprises a first emitter and a second emitter, the first emitter being configured to emit light waves of a first wavelength and the second emitter is configured to emit light waves of a second wavelength, the second wavelength being different from the first wavelength, and the detector comprising at least one optical filter, the radiation source being configured to emit the light waves of the at least one first wavelength and of the second wavelength simultaneously as well as separately from one another;

the cuvette comprising a mirror arrangement with a plane mirror and a concave mirror arranged opposite the plane mirror, wherein an optical axis of the concave mirror is arranged essentially at right angles to the plane mirror, wherein the plane mirror has a first aperture and a second aperture, wherein the first aperture has at least two emitters;

the emitter is configured to emit a spectrum, the full width at half maximum of which is a maximum 50% of the effective wavelength; and

the detector being configured to receive the first and second wavelengths and to separately quantitatively detect an intensity of the emitted light waves of the first wavelength and of the second wavelength.

2. An optical gas sensor in accordance with claim 1, wherein the radiation source is configured to emit a discrete spectrum of light waves, the full width at half maximum of which is a maximum 20% of the effective wavelength.

3. An optical gas sensor in accordance with claim 1, wherein the radiation source and/or the detector are arranged at the plane mirror.

4. An optical gas sensor in accordance with claim 3, wherein the radiation source and the detector are arranged at the cuvette such that light waves emitted by the radiation source reach the detector directly.

5. An optical gas sensor in accordance with claim 1, wherein the radiation source and the detector are arranged at the cuvette such that light waves emitted by the radiation source reach the detector directly.

6. An optical gas sensor in accordance with claim 1, wherein the radiation source is arranged at the cuvette spaced apart from the detector, the emitter being configured to emit light waves with a controlled beam path.

7. An optical gas sensor in accordance with claim 1, wherein the detector is precisely one detector that is arranged at the cuvette.

8. An optical gas sensor in accordance with claim 1, wherein at least two radiation sources are arranged at the cuvette spaced apart from one another.

9. An optical gas sensor in accordance with claim 8, further comprising another detector to provide two detectors, wherein the cuvette comprises at least the two detectors, the two detectors being configured to measure light intensities of different radiation sources or of different emitters of the two radiation sources.

10. An optical gas sensor in accordance with claim 1, wherein:

said detector receives both the first and second wavelengths at a single location.