Gas sensor

• US 7,564,032 B2
• Filed: 09/20/2004
• Issued: 07/21/2009
• Est. Priority Date: 09/24/2003
• Status: Expired due to Fees

• Current Assignee: Berli B.V.
• Original Assignee: Berli B.V.
• Inventors: Boekelman, Willem Antonius
• Primary Examiner(s): Porta; David P
• Assistant Examiner(s): Taningco; Marcus H
• Application Number:
  US10/573,088
• Publication Number:
  US 20060290934A1
• Time in Patent Office: 1,765 Days
• Field of Search: 250/338.1
• US Class Current: 250/338.1
• CPC Class Codes: G01N 21/031 Multipass arrangements
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/3151 using two sources of radiation of different wavelengths G01N21/33 - G01N21/39 take precedence
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis

Abstract

A gas sensor includes at least two light source, projection optics and a light-reflecting chamber provided with at least one light entry opening. The gas sensor further includes a detector that cooperates with the chamber, by means of which detector light from the light source can be detected. The at least two light sources can each be projected on a light entry opening of the chamber by means of the projection optics.

Claims

1. A gas sensor comprising at least two light sources, projection optics and a light-reflecting chamber provided with at least one light entry opening, which gas sensor further comprises a detector that cooperates with the chamber, by means of which detector light from the light source can be detected, wherein the at least two light sources can each be projected on a light entry opening of the chamber by means of said projection optics, and wherein the cross-sectional area of the chamber gradually decreases from the light entry opening in the direction of the detector.

2. The gas sensor of claim 1, wherein the projection optics project each of the light sources on a reduced scale on a light entry opening of the chamber.

3. The gas sensor of claim 1, wherein the at least two light sources can each be projected on the same light entry opening of the chamber by means of projection optics.

4. The gas sensor of claim 3, wherein the light paths between the light sources and the detector are substantially identical.

5. The gas sensor of claim 1, wherein the projection optics comprises at least one projection mirror.

6. The gas sensor of claim 5, wherein the projection mirror is faceted.

7. The gas sensor of claim 5, wherein the mirror comprises a number of segments, a first group of which segments is used for projecting the first light source on the light entry opening whilst the second group of segments is used for projecting the second light source on the light entry opening.

8. The gas sensor of claim 7, wherein the two groups of segments have two different focal points.

9. The gas sensor of claim 1, wherein the light sources are disposed on the same side of the chamber.

10. The gas sensor of claim 1, wherein the light sources are spaced apart by a centre distance in the order of the diameter of the light sources.

11. The gas sensor of claim 1, comprising at least three light sources.

12. The gas sensor of claim 1, wherein the chamber is of square cross-section, at least one side of which cross-section has a dimension in the order of the dimension of a light-receiving element of the detector or of the dimension of the projection of the light source.

13. The gas sensor of claim 1, wherein the length of the chamber is at least three times greater than the cross-sectional dimension of the chamber.

14. The gas sensor of claim 1, wherein the chamber is channel-shaped, at least one dimension of the chamber being in the order of a dimension of a light-receiving surface of the detector.

15. The gas sensor of claim 1, wherein the chamber is provided with a light exit opening, near which light exit opening the detector is mounted.

16. The gas sensor of claim 1, wherein a wavelength-determining element is disposed between at least one light source and the detector.

17. The gas sensor of claim 16, wherein the wavelength-determining element is a filter.

18. The gas sensor of claim 16, wherein the wavelength-determining element is disposed between the light source and the projection optics.

19. The gas sensor of claim 16, wherein the wavelength-determining element is disposed between the projection optics and the detector.

20. A gas sensor comprising at least two light sources, projection optics and a light-reflecting chamber provided with at least one light entry opening, which gas sensor further comprises a detector that cooperates with the chamber, by means of which detector light from the light source can be detected, wherein the at least two light sources can each be projected on a light entry opening of the chamber by means of said projection optics, and wherein the projection optics comprises at least one faceted projection mirror.

21. A gas sensor comprising at least two light sources, projection optics and a light-reflecting chamber provided with at least one light entry opening, which gas sensor further comprises a detector that cooperates with the chamber, by means of which detector light from the light source can be detected, wherein the at least two light sources can each be projected on a light entry opening of the chamber by means of said projection optics, wherein the projection optics comprises at least one projection mirror comprising a number of segments, a first group of which segments being used for projecting the first light source on the light entry opening whilst the second group of segments is used for projecting the second light source on the light entry opening.