Spectroscopic device

Abstract

The invention proposes a spectroscopic device and a spectroscopic method, comprising a tubular measuring cell, in particular, for absorption spectroscopy of contaminated carbon dioxide, wherein the measuring cell is stabilized using at least one tube which is disposed parallel to the direction of extension of the measuring cell and is rigidly connected to the measuring cell.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a schematic view of an inventive spectroscopic device, in particular, for trace analysis of contaminated carbon dioxide.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The inventive spectroscopic device 1 for trace analysis of contaminated carbon dioxide has a measuring cell 2 with a tube 2.1 which surrounds the measuring optics and is closed at the end faces. The tube 2.1 has two gas inlet connecting pieces 2a and 2b via which the measuring cell 2 can be evacuated or filled with a gas for trace analysis, such as e.g. contaminated carbon dioxide. In order to mechanically stabilize the measuring cell 2, the measuring cell in accordance with the invention is rigidly connected to the tubes 3a and 3b using connecting elements 4a and 4b which completely surround the tube periphery and are fixed in the peripheral direction.

In accordance with the invention, the connecting elements 5a and 5b, whose end sides are fixed to the measuring cell 2 and the tubes 3a and 3b, respectively, further enhance stabilization of the measuring cell 2. These have means which can be adjusted and rigidly fixed in accordance with the invention for coupling and removing a measuring beam into or out of the measuring cell 2, to stabilize the measuring beam, and further increase the measuring accuracy, while resulting in a measuring device of maximum compact structure. A first parabolic mirror is integrated in the connecting element 5a disposed on the front side, for feeding and aligning the light beam coupled from the light source 6 into the light guide 6a. Moreover, the connecting element 5b which is disposed at the rear side has a mirror for reflecting the measuring beam, which can be adjusted via adjusting screws 8 such that, in accordance with the invention, the measuring beam passes the measuring cell twice, to double the effective absorption rate compared to single passage of the measuring beam, thereby further increasing the measuring accuracy with maximum compact device size. A second parabolic mirror which is integrated in the connecting element 5a effectively extracts the measuring beam into a light guide 7a. The rear side mirror can be adjusted via the adjusting screws, such that the light beam fed using the first parabolic mirror is reflected by the mirror on the rear side connecting element 5b to the second parabolic mirror and thus into the light guide 7a. This is followed by measurement and evaluation of the absorption spectrum of the decoupled measuring beam in a detector/spectrometer 7 provided for this purpose.

Divergent or convergent lenses (not shown) may moreover be provided for coupling and extracting the light beams into and out of the light guides.

Claims

1. A spectroscopic device comprising: a tubular measuring cell;at least one tube disposed parallel to a direction of extension of said measuring cell; andmeans for rigidly connecting said measuring cell to said tube.

2. The spectroscopic device of claim 1, wherein said measuring cell is rigidly connected on both sides to at least one tube disposed parallel to a direction of extension of said measuring cell.

3. The spectroscopic device of claim 2, wherein tubes are disposed on both sides parallel to said measuring cell and are rigidly connected to each other.

4. The spectroscopic device of claim 1, wherein said at least one tube is formed from a material having a thermal expansion coefficient which is smaller than or equal to that of glass.

5. The spectroscopic device of claim 4, wherein said at least one tube is formed from a same material as said measuring cell.

6. The spectroscopic device of claim 4, wherein said at least one tube is made from glass.

7. The spectroscopic device of claim 1, wherein said connecting means comprises one or more rigid connecting elements disposed on a surface of said at least one tube and on a surface of said measuring cell.

8. The spectroscopic device of claim 1, wherein said connecting means comprises one or two rigid connecting elements disposed on each end of said measuring cell and said at least one tube.

9. The spectroscopic device of claim 7, wherein each of said rigid connecting elements is made from of a material having a heat expansion coefficient which is smaller than or equal to that of glass.

10. The spectroscopic device of claim 8, further comprising a light source, wherein a first end-side connecting element has at least one parabolic mirror for feeding and aligning a light beam from said light source into said measuring cell.

11. The spectroscopic device of claim 10, wherein a second end-side connecting element comprises a mirror for reflecting said light beam in said measuring cell.

12. The spectroscopic device of claim 11, wherein said first end-side connecting element has a further parabolic mirror for decoupling said light beam reflected on said second element.

13. The spectroscopic device of claim 12, further comprising a detector and/or spectrometer to which a decoupled light beam is fed.

14. The spectroscopic device of claim 13, wherein said light source is a light source that radiates in a UV range and said detector or spectrometer comprises a silicon array.

15. The spectroscopic device of claim 13, wherein said light source is a light source that emits light in an infrared range and said detector or spectrometer comprises a HgCdTe array.

16. The spectroscopic device of claim 1, wherein said at least one tube has a same length as said measuring cell.

17. The spectroscopic device of claim 1, wherein said at least one tube has a same diameter as said measuring.

18. The spectroscopic device of claim 1, wherein said measuring cell has a length of between 50 and 150 cm or in a region of 100 cm.

19. The spectroscopic device of claim 1, wherein said measuring cell has a diameter of between 1 and 5 cm or in a region of 3 cm.

20. The spectroscopic device of claim 13, wherein said decoupled light beam is detected by a lock-in amplifier.

21. The spectroscopic device of claim 1, wherein said light beam is coupled from a light guide into said measuring cell and/or is decoupled from said measuring cell into a light guide.

22. The spectroscopic device of claim 1, wherein said measuring cell comprises a thermostat.

23. The spectroscopic device of claim 1, wherein chemically contaminated carbon dioxide is fed into said measuring cell.

24. The spectroscopic device of claim 1, wherein said measuring cell comprises one or more measuring tubes.

25. The spectroscopic device of claim 1, wherein, in a peripheral direction, said measuring cell has at least one further rigid connection to a respective said at least one tube.

26. The spectroscopic device of claim 10, wherein said light source comprises a laser.

27. The spectroscopic device of claim 10, wherein at least portions of said measuring cell define a laser cavity.

28. The spectroscopic device of claim 10, wherein said light source is a spontaneous emission source.

29. A spectroscopic method using the device of claim 1.