EP2622327A1

EP2622327A1 - Flange for closing off an optical device with respect to a sample flow and optical device for partial arrangement in a sample flow

Info

Publication number: EP2622327A1
Application number: EP11761529.4A
Authority: EP
Inventors: Nico Correns; Marion Sobe
Original assignee: Carl Zeiss Microscopy GmbH
Current assignee: Carl Zeiss Microscopy GmbH
Priority date: 2010-09-29
Filing date: 2011-08-26
Publication date: 2013-08-07
Also published as: WO2012041617A1; DE102010047103A1; US20130293886A1

Abstract

When optically irradiating and/or measuring a sample flow through a flange which is arranged in the sample flow and closes off a cavity with respect to the sample flow, there is a continual loss of material through abrasion of wall particles, and therefore the flange has to be regularly exchanged. The invention is intended to make less wear possible. For this purpose, the wall of the flange (1) consists of an elastomeric body (2.3) along a continuous line running around the cavity (3). This makes it possible under point loading for the flange, or at least part of the flange, to undergo movements by which it elastically gives way. This reduces the degree of abrasion of the wall by the sample flow, because a large part of the energy introduced is converted into heat in the elastomeric body.

Description

Flange for terminating an optical device to a sample stream and an optical device for partial placement in a sample stream

The invention relates to a flange for terminating an optical device with respect to a sample stream, comprising a wall comprising a window which at least partially surrounds a cavity, wherein the window has an at least partially transparent filling.

For the purposes of the invention, the sample stream may be either a stream of an object to be examined optically ("material flow") or a stream of an object to be optically irradiated ("irradiation product stream") or a combined measurement and irradiation material stream. Typically this is one

Bulk material flow, but it can also be a cargo flow. The sample stream may be a diverted portion of a main stream. This is usually only the case with material flows. Here, the branched sample stream can be fed back to the main stream after the measurement by the optical device. Alternatively, the sample stream may be discarded after the measurement. However, a measurement and / or irradiation can also take place in the main stream, so that the sample stream is the main stream itself.

The window is in the sense of the invention an opening in the wall, which encloses a window filling, and is part of the wall. The window is therefore included below in the term of the wall unless explicitly stated otherwise. The window filling may be spatially complete or only partially transparent and / or it may be spectrally complete or only partially transparent.

The term light next to visible electromagnetic includes

Radiation also infrared and ultraviolet radiation, as far as it is optically manipulatable.

In the prior art, various optical measuring devices are known, which serve to examine measured goods nondestructive. Such measuring devices are used, inter alia, in agriculture in the classification of Crop and in the food industry for the characterization and monitoring of raw materials. It is also known in the prior art to irradiate samples without optical measurement. For example, drinking water is irradiated with UV light to kill any germs contained.

When using optical devices for irradiating and / or measuring a sample stream, the device interior, for example the light source and / or the optical sensor, must always be protected against contact with the sample stream

Contamination or even damage to the inside of the device should be avoided. As a rule, the sample flow must also be protected from contact with the interior of the device, for example to avoid contamination or losses. The interior of the device is therefore separated from the sample or sample stream by a flange comprising a wall with a window. A deposit on the window can be avoided by a wear-resistant

Window filling material is used and the window by a tilted mounting position of the window or the whole device deflects the incident on the window sample stream by a few degrees. By nachschiebendes measurement and / or irradiation then the previous measurement and / or irradiation material is lifted from the window and pushed on. The window is thereby cleaned simultaneously, so that the operational readiness of the optical device is maintained.

For example, US Pat. Nos. 6,421,990 B1 and WO 2006/035012 A1 describe

spectroscopic measuring devices for agricultural harvesting machines. They comprise a light source which in operation irradiates a sample stream, in particular crop, through a window with light. Light reflected from the sample behind the window is then deflected in a spectrometer by a dispersive element, such as a grating or a prism, in different wavelength-dependent directions. Detector elements of an optoelectronic sensor receive the spectrally split light whose wavelengths are in the visible wavelength range or in the near infrared range at different locations. Through this spatial-spectral splitting on different

Detector elements is an assignment of the measured intensities to disjoint wavelength ranges. The output signals of the detector elements become one Evaluation device supplied, which calculates certain parameters of the sample stream based on the measured spectra.

Despite the wear-resistant wall materials, the sample flow - as a window filling material, for example, produces sapphire for the rest of the wall

For example, steel - a steady loss of material due to removal of

Wandungspartikeln, so that the flange must be replaced regularly. This is costly because the meter must be removed from the sample stream and at least partially disassembled, so the measurement and thus usually the sample stream must be interrupted. It may temporarily result in production stoppage.

The invention has for its object to improve a flange of the type mentioned so that a lesser wear occurs.

The object is achieved by a flange, which in claim 1

having specified features.

Advantageous embodiments of the invention are specified in the subclaims.

According to the invention, it is provided that the wall (apart from the window) consists of an elastomeric body along a closed line running around the cavity. For the purposes of the invention, an elastomeric body is a body which consists entirely or at least essentially of one - in particular in the temperature range between -40 ° C and +70 ° C - elastomeric material or excipient. The elastomeric body may expediently encompass a surface normal of the window and / or an optical axis of the optical device passing through the window. The elastomeric body may also be referred to as an elastic coupling member or elastic member having a (significantly) lower modulus of elasticity than the window. The wall can be integral with the window, so that it consists solely of the elastomeric body. The elastomeric body then has according to the invention a (significantly) lower modulus of elasticity than the window. The wall can be made of several pieces away from the window, so that the elastomeric body only in Area of the closed line is arranged. The elastomeric body then has according to the invention a (significantly) lower modulus of elasticity than at least one of the other wall pieces. Preferably, the elastomeric body has a modulus of elasticity that is (significantly) less than any other

Wandungsstücke.

An elastomeric body has the property over a wide range of

Deformation deformations to be reversibly deformable. The conventional rigid connection within the flange between the surface to the meter and the surface of the material to be measured is thereby canceled. The invention thus allows for selective load elastic deflection movements of the flange or at least a portion of the flange and in particular of the window. In this way, the amount of erosion from the surface of the window and from the remainder of the wall is reduced by the sample flow because a large part of the energy input in the elastomeric body is converted to heat. As an advantageous consequence of the wear of the flange is significantly reduced and extended its life. The risk of sudden destruction is also reduced. After the end of the load, the flange can be steamed in its

Spring back home position.

Conveniently, the wall is substantially a closed at least at one end tube, wherein the window is arranged in the closed end, in particular with different tube cross-sections at different locations of the tube. As a result, the flange can be inserted into an opening, but the optical device remain outside the opening. The term closed here means that the flange is tight against the

Sample stream is. In particular, it may be liquid-tight, in particular watertight, or even gas-tight, in particular airtight, closed. It is also possible to close the flange tube at both ends. Then either a respective window is provided at both ends to allow light to pass through the flange to the optical device, or an optoelectronic detector must be placed inside the tube. In the second case, other optical elements in the

Be arranged inside the tube, for example, a gap and / or

Dispersing agents such as a diffraction grating or a prism. Conveniently, the elastomeric body is - in particular with regard to its rigidity - designed such that in the case of a force acting on the window force (by impacts / blows of particles of the sample stream) at least a portion of the wall, of which in special embodiments, the window, reversible

recedes. The pulse entry into the meter by the impinging

Sample flow is thereby reduced in conjunction with the damping action of the elastomeric body, which reduces mechanical stress (high impact absorption). The retreat can be parallel and / or perpendicular to a longitudinal axis of the tube. In tilted in the sample flow arrangement of the window or the entire flange, which is advantageous for cleaning the window, the largest force components occur in the axial direction of the tube, so that a retreating in this direction causes maximum wear reduction.

Preferably, a stiffness of the elastomeric body depends nonlinearly on a strain (elongation, compression). This applies parallel and / or perpendicular to the longitudinal axis of the tube. Preferably, the stiffness increases exponentially with increasing strain. As a result, excessive deformation widths are prevented. The window is usually designed either as a plane-parallel disc or as an optical lens. As long as the evasive movements of the window are small, the resulting optical error is negligible. The nonlinear

Stiffness thus reduces the risk of irradiation and / or

Measurement inaccuracies.

Advantageously, the elastomeric body may be an adhesive joint. This may be particularly advantageous in embodiments of the flange, which comprise a frame carrying the window, which is connected via the adhesive joint with a base body not located in the sample stream, which in turn serves for connection to the optical device. Alternatively, the base body may be the housing of the measuring device. In a further embodiment in which an elastomeric adhesive joint is advantageous, the window without frame is in contact with the

elastomeric adhesive joint and connected via this with the body. By forming an elastomeric adhesive joint, the required installation space for the flange can be reduced. An elastomeric adhesive joint can for example consist of a soft elastomeric adhesive such as silicone adhesive. Not suitable are brittle-hard adhesives.

Particularly preferred according to the invention are flanges which have a

Include vibration damper. A conventional rigid flange transmits shocks of hard particles contained in the sample stream and any resulting vibrations to the entire optical device and especially the interior of the device. Such mechanical loads can the accuracy of measurement and the

Lifespan of device components. By a

Vibration damping, the potential energy of a reversible deflection of the elastomeric body is converted into internal energy in no time and thus degraded. Resonances are avoided. In addition, the pulse input into the optical device is significantly reduced, thus reducing its mechanical load due to the sample mass flow due to impact and vibration. As a rule, the elastomeric body itself is a vibration damper. As a result, no additional component is needed.

Another embodiment replaces the elastomeric body with resilient members and separate vibration damping members and closes the body

Cavity in the region of the resilient elements with respect to the outside space by means of a closing body such as a foil or a bellows from. These

Embodiment has the same advantages as the embodiment with an elastomeric body, but requires more space and is much more expensive than the inventive solution.

In advantageous embodiments, the elastomeric body encloses a fluid. This allows a reduction in the rigidity of the elastomeric body and

in particular a strong vibration damping. By suitable arrangements of flow channels for the fluid within the elastomeric body, on the one hand the temporal damping characteristic and on the other hand

Elastic behavior depending on the deflection can be specified. An example of an elastomeric body having such flow channels is US 4,765,601. For a first embodiment, it is provided that a non-elastomeric body carries the window, in particular bordered, and is connected to the elastomeric body, in particular by an adhesive or clamped or vulcanized compound. A non-elastomeric support or frame avoids tilting of the window with uneven distribution of the through the sample stream

registered forces.

For a second embodiment, it is provided that the elastomeric body carries or encloses the window, in each case in particular by means of a non-elastomeric support ring. This embodiment makes it possible to dispense with a costly non-elastomeric support body.

Other variants as the two mentioned are possible.

Advantageously, the wall off the window to at least 80% of its volume, in particular at least 90%, more particularly at least 95%, consist of the elastomeric body and in particular a

Non-elastomeric support ring for supporting the window and / or non-elastomeric sockets for receiving fasteners include, in particular with vulcanized arrangement of the sockets in the collar. This embodiment makes it possible to dispense with costly non-elastomeric wall parts largely.

In further embodiments, the window can consist of several layers with different degrees of hardness, in particular with degrees of hardness increasing towards the sample flow, in particular with an outer diamond coating. In connection with the property of the retreating of the window due to the elastomeric body, the so-called eggshell effect can advantageously be avoided, which arises with large hardness differences between different window layers. A diamond-coated sapphire window is particularly preferred.

Preferably, the wall is away from the window of several

connected bodies with different degrees of hardness, in particular with the Sample stream towards increasing degrees of hardness. As a result, a costly hardened material is needed only for the external surfaces in contact with the sample stream. For the substructure, a cost-effective material such as structural steel can be used.

Advantageously, the flange comprises means for equalizing

Air pressure fluctuations in the cavity in elastic deformation of the

elastomeric body, for example as disclosed in WO 02/082153 A1. As a result, internal contamination of the flange is avoided.

Preferably, the flange has a collar for supporting the flange on an outer wall of a sample flow vessel, in particular for fastening the flange to the outer wall.

Advantageously, the flange according to the invention consists of an elastomeric body in which non-elastomeric bushings are arranged for receiving fastening elements, in particular with vulcanized arrangement of the bushes in the collar. Optionally, a non-elastomeric support ring may be provided as a support for the window.

In a flange according to the invention, the frame of the window may be integrally formed with a tube for transporting the sample stream. The pipe is then considered as part of the flange.

The invention also includes an optical device having a flange for illuminating a sample stream through the window and / or for receiving light from a sample stream through the window. In particular, the apparatus may comprise a spectrometer for the spectrally resolved measurement of light falling through the window into the cavity. The flange may be detachably or permanently connected to a housing of the device. In particular, it may be formed integrally with the housing of the device. For the purposes of the invention, light absorption means that light scattered and / or emitted by the sample is recorded. The invention further comprises an optical device having a housing and a flange at least partially enclosing a flange with a window for the partial arrangement of the flange in an opening of a tube for illuminating a (through the tube moving) sample flow through the window and / or Photomicrograph of a sample stream (moving through the tube) through the window, in particular a spectrometer for the spectrally resolved measurement of light falling through the window into the cavity, comprising an elastomeric body for connecting the housing to the tube, in particular for supporting the housing on the pipe. By the elastomeric body, the housing and thus the entire optical device of shock and vibration in the tube is decoupled. Its life can be extended significantly. Preferably bushes are integrated in the connecting elastomeric body, for example, vulcanized, by means of which the elastomeric body can be fastened via fastening elements such as screws on the one hand to the pipe and on the other hand to the housing. Conveniently, the optical device is connected to the tube exclusively via the elastomeric body. The flange may additionally be formed with its own elastomeric body as described above.

The optical devices can have separate windows for lighting and for

Have light.

In particular, the invention comprises an agricultural machine with an optical device with a flange according to the invention, in particular with

Arrangement of the flange of the optical device in an opening of a tube for transporting a sample stream. The pipe may for example be a Abtankrohr a combine harvester or chimney of a forage harvester, through each of which the crop is ejected.

In all embodiments, can serve to attach the flange to the optical device, a base body, preferably not even in the

Sample stream is arranged. Due to the separation of the optical window from the main body of the flange by the elastomeric body can for the

Basic body a less expensive material than for a conventional continuous wall can be used. At the same time, for the

Sample flow exposed wall parts and for the window filling highly wear-resistant materials are used, for example, for the wall carbide, ceramic or the like.

In all embodiments, non-elastomeric wall parts such as the window or the base body may be bonded to the elastomeric body by gluing, clamping or vulcanizing the non-elastomeric wall part concerned. In the case of a metallic support body for the window and a metallic base body may be, for example, a vulcanized rubber-metal compound.

The invention will be explained in more detail by means of exemplary embodiments. In the drawings show:

1 shows a first flange for an optical device in plan view and in cross section,

2 shows the first flange in cross section,

3 shows a second flange in cross section,

4 shows a third flange in cross section,

5 shows a fourth flange in cross section,

6 shows a fifth flange in cross section,

Fig. 7 shows an agricultural machine with an optical measuring device in

Side view and Fig. 8 shows a detail of the chimney of the agricultural machine with the measuring device in side view.

In all drawings, like parts bear like reference numerals.

Fig. 1 shows in the subfigures 1 A and 1 B a flange 1 with a wall 2, which includes a window 2.1, a frame 2.2 for the window, an elastomeric body 2.3 and a base 2.4. Sub-figure 1 B is a cross-section along the marked plane A-A. The tubular wall 2 encloses a cavity 3 partially. The window 2.1 consists, for example

(translucent) sapphire, the frame 2.2 and the base 2.4 consist for example of stainless, unhardened stainless steel. Alternatively, the base body 2.4 made of a less high-quality material, for example

Mild steel, in particular, when it is not exposed to the sample stream. The elastomeric body 2.3 runs as a section of the wall 2 along a closed line around the cavity and consists for example of rubber. In the case shown, it has a hollow cylindrical shape, but it can in other embodiments instead of an annular one

elliptical ring-shaped or polygonal inner and / or outer cross-section. The base body 2.4 has, for example, a collar 2.5 and recesses 2.6, through which a respective fastening element, for example a screw (not shown), can be passed.

The flange 1 is intended for rigid attachment to a housing of an optical device (not shown) and is intended to terminate this against a sample stream (not shown). The housing can also be self-contained and have its own window, in front of which the flange 1 can be mounted by means of the recesses 2.6. Due to the reversibly deformable elastomeric body 2.3, which also acts as a vibration damper, there is no rigid connection between the frame 2.2 together with window 2.1 on the one hand and the base body 2.4 on the other.

The elastomeric body 2.3 is, for example, in a rubber-metal compound produced by vulcanization on the one hand with the frame 2.2 and on the other hand with the Body 2.4 connected. In alternative embodiments, the elastic element can be clamped or glued for connection to these two wall parts 2.2, 2.4. The joints are designed to withstand tensile, compressive, and shear stresses that arise upon contact with the intended sample stream (not shown).

In Fig. 2, a frameless flange 1 is shown in cross section. The window 2.1 is supported by a support ring 2.7, for example made of stainless steel, with which it is glued. The support ring has the task of supporting the window over a large area to local mechanical excess demands of the window material at a

to avoid punctiform loading. The support ring 2.7 is with a

vibration-damping elastic body 2.3 connected, for example vulcanized in this. The elastic body 2.3 is as in Fig. 1 with a

Body 2.4 connected.

In the flange 1 shown in Fig. 3, the elastomeric body 2.3 as

Adhesive gap 2.8 formed, which connects the support ring 2.7 with the base body 2.4.

The correspondingly sized adhesive gap 2.8 simultaneously fulfills the

Function of bonding and a vibration damping elastic

Element.

Fig. 4 shows a flange 1, in which, with the exception of the window 2.1, the entire wall 2 consists of the elastomeric body 2.3. In the collar 2.5 are

Bushes 2.9 vulcanized to form recesses 2.6.

In Fig. 5, a flange 1 is shown in FIG. 1, wherein the base 2.4 to protect the elastomeric body 2.3 has a rotating shield 2.1 1.

Fig. 6 shows a flange 1 according to FIG. 2, wherein the base body 2.4 to protect the elastomeric body 2.3 also has a rotating shield 2.1 1.

In Fig. 7, an agricultural machine 5 is shown in the form of a forage harvester. Processed crop can be discharged through a pipe 6 called a chimney. To determine the quality of the crop is in one Opening of the tube 6, an optical measuring device 7 in the form of a spectrometer (not shown) attached. The measuring device has a flange 1 according to the invention, for example, according to one of the preceding figures, which in the

Sample stream (here identically to the main material flow) protrudes. The housing of the measuring device 7 is for shock absorption exclusively via an elastomeric body 9, which is arranged around the flange 1, connected to the pipe 6.

Fig. 8 shows the tube 6, through which the sample stream P is transported, in an enlarged section. At the flange 1 with the optical window 2.1, for example, up to five tons of samples are passed per minute at a speed of the sample flow P of up to 55 m / s. The measuring device 7 together with the housing and the rigidly connected flange 1 and consequently the window 2.1 are inserted into the tube 6 so that the flange 1 by its mounting position

Sample flow P deflects by a few degrees. By nachschiebende material to be measured, the previous Messgut is pushed. The window is cleaned at the same time. In the measuring device 7, a light source (not shown) for illuminating the sample stream P through the window 2.1 and a spectrometer 8 are arranged. The optical axis of the spectrometer 8 is directed through the window 2.1 of the flange 1 in the tube 6 to spectrally resolved from the sample stream P scattered light to measure. In the flange 1, a pressure compensation valve is 2.10 arranged that

Air pressure fluctuations in the cavity 3, which arise due to volume changes in elastic retreat of the window 2.1 against the sample flow P compensates. In an alternative embodiment, the frame 2.2 of the window 2.1 may be integrally formed with the tube 6.

In all embodiments, the window can be optimally adapted to the required properties by means of a multilayer structure (optical parameters,

mechanical strength and wear protection).

In all embodiments, the concrete modulus of elasticity, the hardness and the geometric shape of the elastic element are to be determined in accordance with the predetermined maximum permissible movement of the window in the optical beam path and the maximum mechanical loading of the wall including the window by the sample mass flow. The geometric shape of the elastomeric Body can be varied in two dimensions. It can have an asymmetrical shape.

The elasticity of the elastomeric body is preferably adjusted so that with average impulse entry on the flange no or only a small

Deflection of a maximum of, for example, between 1/10 mm and 1 mm results and that only for hard impacts / shocks by heavy sample flow particles, a deflection or a deflection of more than 1 mm results.

For example, the invention may be used in transportation, entry and exit control, and processing of herbal, animal, chemical, and pharmaceutical goods, and construction debris. The optical device according to the invention can be used in control circuits for mixing devices of a first mass flow with a second mass flow or for monitoring manual additives to a

Mass flow can be used. In particular, it may be attached to lines from and / or to feed silos and granaries. It can be used to monitor the cleaning of transport tubes by purging a transport tube several times with a constant amount of solvent for a contaminant until the determined by the device concentration of the contaminant in the solvent is at least almost constant. The amount of solvent can be the same in each rinse or fresh solvent can be used in each case.

LIST OF REFERENCE NUMBERS

1 flange

2 wall

2.1 window

2.2 framework

2.3 Elastomeric body

2.4 basic body

2.5 collar

2.6 recess

2.7 Support ring

2.8 glue joint

2.9 socket

2.10 Pressure balance valve

2.1 1 sign

3 cavity

4 socket

5 Agricultural machine

6 tube

7 Optical device

8 spectrometers

9 Elastomeric connector body

P sample stream

OA optical axis

Claims

claims

1 . Flange (1) for terminating an optical device (10) with respect to a

Sample stream (P), comprising a wall (2) comprising a window (2.1) which encloses a cavity (3) at least partially, wherein the window (2.1) has an at least partially transparent filling, characterized in that the wall along a the cavity (3) extending around, closed line of an elastomeric body (2.3) consists.

2. Flange (1) according to claim 1, wherein the wall (2) is substantially a

closed tube is at least at one end and the window (2.1) is arranged in the closed end, in particular with different tube cross-sections at different locations of the tube.

3. flange (1) according to claim 2, wherein the elastomeric body (2.3) in such a way

is formed, that in the case of one on the window (2.1) acting

Force component which is parallel to a longitudinal axis of the tube, at least a part of the wall (2), of which in particular the window (2.1) reversibly recedes.

4. flange (1) according to claim 1, 2 or 3, wherein a stiffness of the elastomeric body (2.3) depends non-linearly on a deflection.

5. flange (1) according to any one of the preceding claims, wherein the elastomeric body (2.3) is an adhesive joint (2.8).

6. Flange (1) according to one of the preceding claims, a

Comprising vibration damper (2.3).

7. flange (1) according to any one of the preceding claims, wherein the elastomeric body (2.3) enclosing a fluid, in particular for vibration damping.

8. flange (1) according to any one of claims 1 to 5, wherein a non-elastomeric

Body (2.3) carries the window (2.1), in particular bordered, and with the elastomeric body (2.3) is connected, in particular by an adhesive or clamped or vulcanized compound.

9. flange (1) according to one of claims 1 to 5, wherein the elastomeric body (2.3) carries or encloses the window (2.3), in each case in particular by means of a

non-elastomeric support ring.

10. flange (1) according to any one of the preceding claims, wherein the wall (2) away from the window (2.1) to at least 80% of its volume, in particular at least 90%, more particularly at least 95%, from the elastomeric body (2.3 ), in particular comprising a non-elastomeric support ring for supporting the window (2.1) and / or non-elastomeric bushings (2.9) for receiving fasteners, in particular with vulcanized arrangement of the bushes (2.9) in the collar (2.5).

1 1. Flange (1) according to one of the preceding claims, wherein the window (2.1) consists of several layers with different degrees of hardness,

in particular with hardness increasing towards the sample stream,

in particular with an outer diamond coating.

12. Flange (1) according to any one of the preceding claims, wherein the wall (2) off the window (2.1) consists of several connected bodies (2.2, 2.3, 2.4) with different degrees of hardness, in particular with the sample stream (P) towards increasing degrees of hardness ,

13. Flange (1) according to one of the preceding claims, comprising means for compensating for air pressure fluctuations in the cavity (3) upon elastic deformation of the elastomeric body (2.3).

14. Flange (1) according to one of the preceding claims, a collar (2.4)

having for supporting the flange (1) on an outer wall of a

Sample flow vessel, in particular for securing the flange (1) on the outer wall.

15. Flange (1) according to the preceding claim, wherein the collar (2.5) consists of an elastomeric body, are arranged in the non-elastomeric sockets (2.9) for receiving fasteners, in particular with vulcanized arrangement of the sockets (2.9) in the collar ( 2.5).

16. Optical device (7) for partial arrangement in a sample stream (P), with a flange (1) according to one of the preceding claims for illuminating the sample stream (P) through the window (2.1) and / or for light absorption from the sample stream ( P) through the window (2.1), in particular with a

Spectrometer (8) for the spectrally resolved measurement of light falling through the window (2.1) into the cavity.

17. Optical device (7) with a housing and a cavity at least partially enclosing flange (1) with a window (2.1) for the partial arrangement of the flange (1) in an opening of a tube (6) for illuminating a sample stream (P) through the window (2.1) and / or for the light absorption of a sample stream (P) through the window (2.1), in particular with a

Spectrometer (8) for the spectrally resolved measurement of light falling through the window (2.1) into the cavity, characterized by an elastomeric body (9) for connecting the housing to the tube (6), in particular for supporting the housing on the tube (6 ), in particular with formation of the flange according to one of claims 1 to 15.

18. Agricultural machine (5) with an optical device (7) according to

Claim 16 or 17, in particular with arrangement of the flange (1) of the optical device (7) in an opening of a tube (6) for transporting a sample stream (P).