Miniaturised spectrometer

• US 20040017567A1
• Filed: 03/11/2003
• Published: 01/29/2004
• Est. Priority Date: 12/22/1999
• Status: Active Grant

• Current Assignee: Scan Messtechnik Gesellschaft Mbh
• Original Assignee: Scan Messtechnik Gesellschaft Mbh
• Inventors: Weingartner, Wendelin, Loicht, Martin, Fleischmann, Nikolaus, Zipper, Thomas, Weingartner, Bernhard, Weingartner, Andreas
• Granted Patent: US 6,956,648 B2
• Time in Patent Office: Days
• US Class Current: 356/326
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0227 using notch filters
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0232 using shutters
• CPC Class Codes: G01J 3/0256 Compact construction
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01N 2021/3509 Correlation method, e.g. one beam alternating in correlator/sample field
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/8507 Probe photometers, i.e. with optical measuring part dipped into fluid sample

Abstract

The invention concerns a miniaturized spectrometer, especially in the form of a probe, for determination of the ingredients of a gaseous or liquid fluid with a light source (3) and a spectrometer (2), at least one measurement beam and at least one reference beam.

The invention is characterized by the fact that the light of the light source (3) is optionally fanned out and bundled by means of at least one optical lens (8) to an essentially parallel beam, that at least one measurement beam is passed through a light transparent window from the probe into the fluid being investigated and through an additional light transparent window back into the probe, that at least one reference beam is guided in the probe interior, that a collecting optics (14), consisting of at least one lens, diverts the beams to the impingement point of the light guide (5) or the inlet of the spectrometer (2), and that a beam selector (7) is provided in the region of the collecting optics (14) that passes through one of the partial beams and interrupts all the others.

Claims

1. Miniaturized spectrometer for determination of the ingredients of a gaseous or liquid fluid with a light source (3) and a spectrometer (2), with at least one measurement beam and at least one reference beam, in which the light of the light source (3) is optionally fanned out and bundled by means of at least one optical lens (8) to an essentially parallel beam, at least one measurement beam being passed through the fluid being investigated and at least one reference beam being passed along the fluid being investigated, in which a collecting optics (14), consisting of at least one lens, diverts the beams to the impingement point of a light guide (5) or the inlet of a spectrometer (2), and in which a beam selector (7, 7′

) is provided that passes through one of the partial beams and interrupts all the others,

characterized by the fact

that the spectrometer has the shape of a probe, that at least one measurement beam is passed through a light transparent window from the probe into the fluid being investigated and through an additional light transparent window back into the probe, that at least one reference beam is guided in the probe interior, and that the beam selector (7, 7′

) is arranged in the region of the collecting optics (14).

2. Spectrometer according to claim 1, characterized by the fact that the beam selector (7) consists of a pin diaphragm, essentially rotatable around an axis parallel to the beam axis, with one passage opening (20) for each of the partial beams, in which the pin diaphragm is movable, preferably rotatable, in a plane that lies essentially normal to the beam axis.

3. Spectrometer according to claim 1, characterized by the fact that the beam selector (7′

) consists of a drum, rotatable essentially around an axis normal to the beam axis, with a passage opening (20) for each of the partial beams, in which the passage openings (20′

) are arranged offset relative to each other in the axial and peripheral direction.

4. Spectrometer according to one of the preceding claims, characterized by the fact that a standard beam is formed that is guided over a length in the fluid that is different from the corresponding length of the measurement beam.

5. Spectrometer according to one of the preceding claims, characterized by the fact that the distance measured in the beam direction between the impingement point of the light guide (5) or the inlet of the spectrometer (2) and the beam focusing by shifting of light guide (5) and/or collecting optics (14) and/or lamp (3) and/or optics (8) is variable.

6. Spectrometer according to one of the preceding claims, characterized by the fact that an exchangeable or adjustable diaphragm, for example, an iris diaphragm with variable hole diameter, is arranged in the region of optics (8) and blanks out at least one of the partial beams.

7. Spectrometer according to one of the preceding claims, characterized by the fact that an optical diffusor is arranged in the beam path, preferably right at the focal distance of the light source.