IR spectroscopy analysis apparatus with coupling device

Abstract

An apparatus for the analysis of a sample by means of an infrared (IR) spectroscopy, comprising a vessel (1) rotating during operation for holding the sample, a measuring head (2, 2′) connected with the vessel, a spectrometer (8) which is supplied with IR radiation reflected by the sample, and at least one first optical fiber element (4a) for transmitting the IR radiation reflected by the sample, is characterized in that the spectrometer (8) is stationary and a first rotary feed through (7, 7′, 7a, 7a′) is provided for coupling the reflected IR radiation from the first optical fiber element (4a) into a second optical fiber element (4b), in which the first optical fiber element (4a) is connected with the rotating part of the first rotary feed through (7, 7′, 7a, 7a′) and the spectrometer (8) is connected with the stationary part of the first rotary feed through (7, 7′, 7a, 7a′) via the second optical fiber element (4b). The apparatus according to the invention ensures sufficient stability, requires little space and allows for the use of powerful spectrometers.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a schematic cross-section through an analysis apparatus according to the invention with an IR light source integrated in a measuring head.

FIG. 2 shows a schematic cross-section through an analysis apparatus according to the invention with a two-sided vessel suspension and an IR light source integrated in a measuring head.

FIG. 3 a shows a schematic cross-section through an analysis apparatus according to the invention with a stationary IR light source.

FIG. 3 b shows a schematic cross-section through two optical fiber elements of an analysis apparatus according to the invention, forming a glass fiber bundle.

FIG. 4 shows a schematic cross-section through an analysis apparatus according to the invention with a two-sided vessel suspension and a stationary IR light source.

FIG. 5 shows a schematic cross-section through an analysis apparatus according to the invention with an eccentric arrangement of the measuring head.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows an analysis apparatus according to the invention, especially for mixing and drying processes, with a measuring head 2 located outside a vessel 1. The measuring head 2 comprises an IR light source 3 for illuminating the sample. An optics 6 receives the IR radiation reflected by the sample. In the embodiment shown in FIG. 1, the sample is irradiated with the IR radiation through a window 5 integrated in the vessel 1, “window” meaning an IR-permeable area of the vessel 1. The measuring head 2 can be mounted directly to the window 5, particularly flanged, or to a frame (not shown) in which the vessel is hung and which rotates with the vessel.

The IR radiation emanating from the sample is focused through the optics 6 and coupled in a first optical fiber element 4a. The optics 6 can, for example, be a suitably formed end of the first optical fiber element 4a. It is nevertheless also possible to provide further optical elements such as lenses or mirrors for focusing the IR radiation. In a preferable version of the apparatus according to the invention, the IR light source 3 is formed as an illumination ring in the center of which the optics 6 is located. It can also be advantageous to arrange the first optical fiber element 4a in the form of an hoptical fiber bundle around the IR light source 3.

The first optical fiber element 4a transmits the IR radiation to a first rotary feed through 7. The rotary feed through 7 consists of a rotary part and a stationary part, the rotary part being connected with the first optical fiber element 4a and the stationary part with a second optical fiber element 4b. The second optical fiber element 4b leads to a spectrometer 8 in which the detected signals are processed. The connection of the IR light source 3 with the spectrometer 8 is carried out via electrical leads 9a, 9b. The electrical leads 9a, 9b are connected with each other in the first rotary feed through 7 via sliding contacts so that the IR light source 3 can be energized during operation. The rotary feed through 7 allows for the transmission of the optical or electrical signals between the spectrometer 8 and the measuring head 2, which is an interface between the sample and the spectrometer 8. In the embodiment shown in FIG. 1, the measuring head 2 is arranged coaxially to a suspension 10 around the axis of which the vessel 1 is rotated. Nevertheless, there are also different arrangements possible. Moreover, the rotation of the vessel can also be carried out by wobbling. The drive for the rotary motion is not shown in the figures.

FIG. 2 shows a version of the apparatus according to the invention in which the vessel 1 is fixed at two opposing suspensions 10a, 10b. In this way, the apparatus can withstand high loads, which is especially advantageous when using large mixing vessels.

The electrical lead 9b and the first optical fiber element 4a each run in one of the suspensions 10a, 10b of the vessel so that they are inducted into the vessel 1 at opposing sides. It is nevertheless also possible to implement the access for the electrical lead 9b and the first optical fiber element 4a not via the suspensions 10a, 10b but outside the rotary axis. It is also possible to introduce the electrical lead 9b and the first optical fiber element 4a together via an access to the interior of the vessel 1. While the connection of the first optical fiber element 4a with the second optical fiber element 4b is effected via a first rotary feed through 7a, a separate, second rotary feed through 7b is provided for the connection of the electrical lead 9b with the electrical lead 9a.

Apart from the spectrometer 8, the IR light source 3 can also be arranged externally in order to reduce the weight of the rotating parts. FIG. 3a shows such an arrangement. The IR radiation emanating from the IR light source 3 is transmitted to a measuring head 2′ via a third optical fiber element 11a and a fourth optical fiber element 11b, the coupling of the IR radiation being effected from the third optical fiber element 11a into the fourth optical fiber element 11b via a rotary feed through 7′. It is especially advantageous when the first and fourth optical fiber elements 4a, 11b as well as the second and third optical fiber element 4b, 11a are combined to one bundle each at least in the area of the rotary feed through 7′, as shown in FIG. 3b for the first and fourth optical fiber elements 4a, 11b. The first optical fiber element 4a consists of one single glass fiber and is surrounded by the fourth optical fiber element 11b in the form of a glass fiber ring. In this way, the coupling of the optical fiber elements 4a, 4b, 11a, 11b can be implemented via just one single rotary feed through 7′. The first optical fiber element 4a can also comprise a number of glass fibers surrounded by the glass fibers of the fourth optical fiber element 11b.

FIG. 4 shows another version of the analysis apparatus according to the invention with an external IR light source 3. Here, two separate rotary feed throughs 7a′, 7b′ are used for the couplings of the optical fiber elements 4a, 4b, 11a, 11b, for the transmission of the radiation.

FIG. 5 shows a version of the apparatus according to the invention with an external IR light source 3 in which the measuring head 2′ as well as the window 5 of the vessel 1 are arranged not along but eccentrically as to the rotary axis of the vessel 1.

The measuring head 2 can be arranged outside as well as inside the vessel 1 irrespective of the kind of suspension of the vessel 1.

REFERENCE NUMERAL LIST

1 Vessel

2, 2′ Measuring head

3 IR light source

4 a First optical fiber element

4 b Second optical fiber element

5 Window

6 Optics

7, 7′, 7a, 7a′ First rotary feed through

7 b, 7b′ Second rotary feed through

8 Spectrometer

9 a, 9b Electrical leads

10, 10a, 10b Suspension

11 a Third optical fiber element

11 b Fourth optical fiber element ] http://www.pharmaceutical- hnology.com/contractors/lab-equip/carl-zeiss/carl_zeiss2. html Production Scale Blenders - Blending Systems; Pharmatech, tp://www.pharmatech.co.uk/pdf/ProductionBlenders.pdf

Claims

1. An apparatus for the analysis of a sample by means of infrared (IR) spectroscopy, the apparatus comprising: a vessel for holding the sample;means for rotating said vessel;a measuring head cooperating with said vessel;a first rotary feed-through, said first feed-through having a rotating part and a stationary part;at least one first optical fiber element for transmitting IR radiation reflected from the sample, said first fiber element being a single optical fiber or a bundle of several optical fibers, said first fiber element connected between said measuring head and said rotating part of said first rotary feed-through;a stationary spectrometer; anda second optical fiber element connected between said spectrometer and said stationary part of said first rotary feed-through, wherein the reflected IR radiation from the sample is passed from said first optical element to said second optical element and into said spectrometer.

2. The apparatus of claim 1, wherein said measuring head comprises at least one IR light source with which the sample is illuminated.

3. The apparatus of claim 2, further comprising sliding contacts at said first rotary feed through via which said IR light source is energized.

4. The apparatus of claim 2, wherein said IR light source is stationary.

5. The apparatus of claim 4, wherein said first and second optical fiber elements are each designed as individual optical fibers and said second optical fiber element comprises a beam splitter for coupling in IR light of the stationary IR light source.

6. The apparatus of claim 4, further comprising an illumination optics for illumination of the sample, said illumination optics having a third optical fiber element and a fourth optical fiber element, said third optical fiber element being connected to said IR light source and said fourth optical fiber element transmitting IR radiation from the IR light source to the sample.

7. The apparatus of claim 6, wherein said third optical fiber element is connected to said stationary part and said fourth optical fiber element is connected to said rotating part of said first rotary feed through, wherein either said first and second optical fiber elements or said third and fourth optical fiber elements are designed as ring-shaped optical fiber bundles in said first rotary feed through.

8. The apparatus of claim 6, wherein said vessel comprises two rotatable suspensions, said third optical fiber element being connected to a stationary part and said fourth optical fiber element to a rotating part of a second rotary feed through, said first rotary feed through being arranged at said first suspension and said second rotary feed through at said second suspension.

9. The apparatus of claim 1, wherein said vessel has a window and said measuring head is located at said window.

10. The apparatus of claim 9, wherein said measuring head is flanged at said window.

11. The apparatus of claim 9, wherein said window of said vessel is eccentric with respect to a rotary axis of said vessel.

12. The apparatus of claim 1, wherein said spectrometer is a Fourier spectrometer.