Analysis device for spectral analysis and closure unit for same

Abstract

The present invention relates to a closure unit (08) for an analysis device for the spectral analysis of a sample which has been taken, for example, from an agricultural product, animal feed or foodstuff. The closure unit (08) comprises a pivotable cover (09) for covering a sample container (06) of the analysis device. The closure unit (08) additionally comprises a pressure plate (11) for exerting a pressing force on a sample located in the sample container (06). The pressure plate (11) is arranged under the cover (09) and held on the cover (09). The pressure plate (11) can be displaced with respect to the cover (09) counter to a force of a pressure spring (17). The invention further relates to an analysis device having the closure unit (08) according to the invention.

Description

[0001] Analytical device for spectral analysis and closure unit for this purpose

[0002] The present invention relates firstly to a closure unit for an analytical instrument for the spectral analysis of a sample, which, for example, has been taken from an agricultural product, animal feed, or foodstuff. Furthermore, the invention relates to an analytical instrument with the closure unit according to the invention.

[0003] German patent DE 10 2006 018 926 A1 discloses a sample stage for a food analysis device for analyzing a food sample. The sample stage comprises a sample holder for receiving the food sample, a moving mechanism for moving the sample holder, and a housing surrounding the moving mechanism. The moving mechanism and the sample holder are magnetically coupled, allowing the sample holder to move outside the housing relative to the housing.

[0004] EP 3 978 918 Al discloses an automatic sample dispenser for dispensing samples. The sample dispenser includes a sample tray which is movable between a number of dispensing positions. The sample dispenser also includes a contactless coupling for moving the sample tray between the number of dispensing positions.

[0005] CN 213275351 U shows a device for the fluorescence detection of food. The reaction of luciferase with ATP is intended to detect human cells, bacteria, molds, and food residues. It aims to solve the problem that a test tube cannot be fixed in place after being inserted into a detection device, as this could cause it to strike the inner wall of the detection opening and be damaged. The device, formed by a fluorescence detector, is intended for a food production line and includes a sealing cap hinged to the outer surface of the upper end of the fluorescence detector. At the upper end of the fluorescence detector is a groove with detection sockets on both sides in the center. A clamping and fastening mechanism, firmly connected to the fluorescence detector, is located on the top of the detection sockets.On the inner surface of the upper end of the fluorescence detector, there is a mounting block inside the cover.

[0006] CN 206683929 U shows a high-temperature sealing cage for colorimetric tubes. A base extends through a connecting rod and is connected to a positioning disc. One end of the positioning disc passes through a hinge seat and a damping hinge, as well as a stuffing box connection. The other end of the positioning disc passes through a support and supports the stuffing box. A locking handle secures the stuffing box and the positioning disc. A circular, conical coil spring is mounted in a circular recess in the underside of the stuffing box. A pressure plate is positioned by the circular, conical coil spring.

[0007] German patent DE 100 02 920 describes a device for contacting biological substances immobilized on a surface with a solution of biological substances. The device comprises a chamber for receiving the solution. The bottom of the chamber is formed by the surface. A top of the chamber is formed by a lid. The side walls of the chamber are formed by a seal. Springs exert constant pressure on the seal. EP 2 266 693 discloses a refractometer with a housing, a measuring cell arranged in the housing, and a lid unit. The lid unit has a base plate with a recess providing access to the measuring cell of the refractometer and a lid for covering the measuring cell. The lid is connected to the base plate by a hinge. The lid unit also has a lid insert that is replaceable in the lid.The lid unit is detachably connected to the housing via a connecting element linked to the base plate.

[0008] In the article by Reinhard Resch: “Determination of dry matter content of fresh grass samples using the ZEISS CORONA 45VISNIR DA spectrometer”, Annual Meeting 2008 of the Working Group for Food, Veterinary and Agricultural Affairs (ALVA), LFZ Raumberg-Gumpenstein, Irdning (Austria), ISSN 1606-612X, https: / / raumberg-gumpenstein.at / jdownloads / FODOK / 2008 / fodok_2_4935_08_05_26_ALVA-Tagung_NIRS_Resch.pdf, the use of a diode spectrometer for determining the dry matter content of fresh green fodder samples is described. It has been shown that the measured reflection spectra depend on the sample contact pressure, so a defined contact pressure is useful for such a sample material.

[0009] The object of the present invention, starting from the prior art, is to enable a spectral analysis of a sample of an agricultural product, animal feed, foodstuff, or other substance, in which improved and reproducible measurement results can be obtained without requiring increased effort from the operator. This object is achieved by a closure unit according to claim 1 and by an analytical instrument according to dependent claim 15.

[0010] The closure unit according to the invention is designed for an analytical instrument for the spectral analysis of a sample. The analytical instrument is preferably designed for mobile use. The analytical instrument is preferably designed as a portable tabletop device.

[0011] The analytical instrument is preferably designed for the spectral analysis of a sample of an agricultural product, animal feed, or foodstuff. The sample could, for example, be chopped plants such as grass or corn, or a mixed feed sample. In principle, however, it could also be a sample of another substance, such as an inorganic substance. The spectral analysis is intended to determine at least one component of the sample. In particular, the quantitative proportion of this at least one component is to be determined. The component is preferably water, so that the spectral analysis determines the moisture content of the sample.The ingredient can also be composed of at least one protein, at least one oil, at least one sugar, at least one starch, nicotine, gluten, at least one crude fiber, or a combination of these substances. Preferably, the proportions of several of the ingredients in the sample are determined.

[0012] Spectral analysis is preferably performed by reflection spectroscopy. For this purpose, the sample is irradiated with electromagnetic radiation, preferably UV radiation, visible light, and / or IR radiation, preferably NIR radiation. The electromagnetic radiation has a wavelength range that preferably extends over at least 500 nm and more preferably over at least 1,000 nm. The analytical instrument comprises a radiation source for generating the electromagnetic radiation. The radiation source is preferably at least one halogen lamp, at least one thermal radiator, and / or at least one LED. The sample reflects the electromagnetic radiation, and the reflected radiation is spectrally detected by a spectrometer. The analytical instrument can also be configured for other spectroscopic methods.

[0013] The analyzer comprises a base unit in which the radiation source, the spectrometer, and control and evaluation electronics are preferably arranged. The base unit also includes a sample container holder. The sample container holder is preferably designed to rotate the sample container inserted therein. Preferably, the sample container holder is designed to transmit a torque to the sample container via a magnetic field to rotate it, thus eliminating the need for mechanical coupling of the sample container. However, any type of coupling for rotating the sample container can be implemented. For spectral analysis, the sample is placed in the sample container, which is then positioned in the sample container holder.The analyzer is designed to direct the electromagnetic radiation generated by the radiation source onto the sample in the sample container and to direct the radiation reflected from the sample to the spectrometer.

[0014] Preferably, the sample container holder is designed to hold the

[0015] The sample container is reproducibly mounted. Preferably, the sample container mount is designed to mount the sample container centrally within the mount.

[0016] The sample container preferably has the shape of a cup. The sample container preferably has the shape of a hollow cylinder open at the top. The sample container preferably has a bottom that is transparent to the radiation generated by the radiation source and to the radiation reflected by the sample.

[0017] The sealing unit serves to close the analyzer and the sample container within it, thus protecting the sample from external influences, particularly UV radiation, visible light, and IR radiation. This ensures an accurate spectral analysis of the sample.

[0018] The closure unit comprises a lid for covering the sample container and ultimately for closing the analyzer. The lid preferably has the form of a hood. The lid is designed to cover the sample container and the sample container holder from above. The lid shields the sample container and the sample it contains from electromagnetic radiation, such as, in particular, UV radiation, visible light, and IR radiation. Therefore, the lid is preferably opaque to UV radiation, visible light, and / or IR radiation. The lid preferably seals the analyzer tightly against external UV radiation, external visible light, and / or external IR radiation.

[0019] The closure unit includes a pressure plate for exerting pressure on the sample inside the sample container. This pressure acts from above, compressing the sample to a desired degree to ensure defined conditions for spectral analysis. For this purpose, the pressure plate is positioned beneath the lid. It is held by the lid so that it moves with the lid and is supported by it. The pressure plate is displaceable against the lid against the force of a spring. The closure unit is designed such that when the lid is closed, the pressure plate is located inside the sample container and exerts pressure on the sample, exerted by the spring.The pressure plate is preferably rotatably mounted about an axis opposite the lid, so that the pressure plate, along with the sample container and the sample contained therein, can rotate within the analyzer. This axis is preferably vertically oriented when the lid closes the analyzer.

[0020] A particular advantage of the closure unit according to the invention is that simply closing the analytical instrument mechanically ensures that a defined and constant contact pressure is applied to the sample. No additional action or attention from the operator is required.

[0021] In preferred embodiments, the closure unit further comprises a pivot bearing for the lid. In this pivot bearing, the lid can be pivoted from a covered position, concealing the sample container, to an open position, and vice versa. The pivot bearing is preferably arranged laterally next to the lid. One axis of the pivot bearing is preferably horizontally oriented. The open position is used to fill the sample container with the sample or to place the filled sample container in the sample container holder. In the open position, the lid is preferably arranged vertically. The covered position is preferably used to initiate the process of closing the analyzer, and ultimately to close the analyzer. In the covered position, the lid is preferably arranged horizontally.The lid can be pivoted in the pivot bearing by a pivot angle, which is preferably at least 90°.

[0022] In preferred embodiments, the closure unit further comprises a guide unit for guiding the pivot bearing relative to the base of the analyzer. The guide unit is fixed in the base. The guide unit serves, in particular, to linearly guide the pivot bearing in a vertical direction relative to the base of the analyzer. The pivot bearing is displaceable within the guide unit relative to the base in order to move the lid, when in the closed position, towards and away from the sample container located in the base. Thus, the lid, when in the closed position, can be moved, in particular, upwards and downwards. In these embodiments, the process of closing the analyzer comprises two phases.In the first phase, the lid is pivoted from the open position to the closed position, thereby positioning the pressure plate above the sample, while still maintaining a vertical distance from it. In the second phase, the lid, held by the pivot bearing, is moved downwards by the guide unit. This movement brings the lid into a position where it closes the analyzer. Simultaneously, the pressure plate is pressed onto the sample and moved vertically against the lid against the force of the pressure spring, thus exerting pressure on the sample. In these configurations, the opening process of the analyzer comprises two phases. In the first phase, the lid, held by the pivot bearing, is moved upwards, again facilitated by the guide unit.First, the lid is moved to a position where it no longer seals the analyzer but remains in the covered position. Second, the pressure plate is lifted away from the sample, releasing the pressure spring and pushing the pressure plate back into place. In the second phase, the lid, mounted on a pivot bearing, is pivoted from the covered position to the open position, releasing the pressure plate and lid from the sample container.

[0023] In preferred embodiments, the guide unit comprises at least one guide rail in which a guide carriage runs. The at least one guide rail is preferably arranged vertically and attached to the device base. The at least one guide carriage supports the pivot bearing with the cover mounted therein.

[0024] In alternative preferred embodiments, the guide unit is telescopically designed and comprises at least two telescoping sections that can be moved into one another. The telescoping sections preferably have a non-circular cross-section, so that they cannot be rotated relative to each other, thus preventing the cover from rotating about the vertical axis relative to the device body. The telescoping sections preferably have a rectangular or square cross-section. The outer telescoping section is preferably fixed in the device body; preferably by being embedded in the plastic device body. The pivot bearing is preferably attached to the inner telescoping section.In preferred embodiments, the pivot bearing is locked to fix the lid in the covered position when the pivot bearing in the guide unit is displaced to a position below its uppermost position. The lid cannot be pivoted when the pivot bearing is locked. Preferably, the lid can only pivot in the pivot bearing when the pivot bearing is in its uppermost position in the guide unit, in which position the pivot bearing is not locked. Locking the pivot bearing allows for the orderly execution of the two phases of closing and opening the analyzer described above. In the second phase of closing the analyzer, the lid is prevented from pivoting back from the covered position, which would otherwise result in the lid not closing correctly or the pressure plate becoming jammed in the sample container.Even in the first phase of opening the analyzer, it is prevented that the lid swings out of the covering position, which would cause the pressure plate to become jammed in the sample container.

[0025] In preferred embodiments, the locking unit further comprises a releasable detent for locking the pivot bearing, which is displaced to a lower position within the guide unit. When the pivot bearing is in this lower position, the cover held by the pivot bearing is displaced downwards to such an extent that it closes the analyzer. The detent prevents any displacement of the pivot bearing and thus also any displacement of the cover held by the pivot bearing upwards within the guide unit. Therefore, the detent serves to fix the cover closing the analyzer in this position until the detent is released. This position constitutes a closed position. The detent is preferably designed to lock the pivot bearing, which is displaced to its lowest position within the guide unit. The detent preferably comprises a locking bolt and a locking bolt receptacle.The locking bolt is preferably attached to a movable element of the guide unit, while the locking bolt receptacle is fixedly connected to the device body. Preferably, the locking bolt is attached to the guide carriage or the inner telescopic section. The locking bolt can also be designed as a hook. The locking mechanism is mechanically or, preferably, electromechanically releasable. Preferably, the locking bolt receptacle includes an electromagnet that can hold and release the locking bolt, for which the electromagnet must be energized or de-energized. The analyzer preferably has an electrical push button or switch to control the energization of the electromagnet.

[0026] In preferred embodiments, the guide unit includes a lifting spring for raising the pivot bearing with the lid mounted therein. This lifting spring forces the lid upwards into its uppermost position. A force from this lifting spring must be overcome to move the lid downwards and thus close the analyzer. Simultaneously, the force of the pressure spring must be overcome, which also forces the lid upwards as soon as the pressure plate rests on the sample. The downward force consists of the weight of the lid and the pivot bearing, as well as the force applied by the operator to close the analyzer. The upward force consists of the lifting spring and the force of the pressure spring as soon as the pressure plate rests on the sample.If the upward forces are greater than the downward forces, the pivot bearing, with the lid mounted within it, moves upwards, thus enabling this phase of opening the analyzer to occur automatically. For example, the weight of the lid and pivot bearing is 12 N, while the force of the pressure spring is 30 N and the force of the lifting spring is 20 N. Therefore, the operator only needs to apply a force of 38 N by hand to close the analyzer. Since the force of the lifting spring (20 N, for example) is greater than the weight (12 N, for example), the lifting spring raises the pivot bearing with the lid mounted within it as soon as the operator releases any force, and even after the pressure plate has been removed from the sample and the pressure spring is no longer exerting an upward force.The lifting spring is preferably formed by a gas spring, so that the pivot bearing with the cover mounted therein does not spring upwards at high speed when the locking mechanism is released. Alternatively, the lifting spring is preferably formed by a metallic tension or compression spring, wherein the displacement movement of the guide unit preferably occurs against a volume limited by an outlet valve, so that the displacement movement is damped by air in that volume.

[0027] In those embodiments where the guide unit is telescopic, the lifting spring is preferably formed by a spiral compression spring, which is arranged in the outer telescopic section and acts on the inner telescopic section. The outlet valve is preferably arranged in the upper axial end of the inner telescopic section, through which air flows from the volume inside the telescopic section when the telescopic sections are moved relative to each other.

[0028] In preferred embodiments, the closure unit further comprises a control device that allows monitoring of whether the pressure spring is deflected between a minimum necessary deflection and a maximum permissible deflection when the pressure plate is pressed against the sample, particularly when the analyzer is closed. The closure unit is intended to ensure that a defined pressure is applied to the sample. This is the case when the pressure spring, in the closed state of the analyzer, is deflected by a specific amount that lies between the minimum necessary deflection and the maximum permissible deflection. Within this range, the force of the pressure spring is sufficient to exert the defined pressure on the sample.In the simplest case, the control device is formed by a mechanical indicator, which includes a pointing element connected to the pressure plate and two markings for the minimum required deflection and for the maximum permissible deflection. In preferred cases.

[0029] In its various forms, the control device comprises at least one sensor for detecting the deflection of the pressure spring and a signal transmitter for indicating when the deflection falls below the minimum required value or exceeds the maximum permissible value. The signal transmitter is preferably optical or acoustic. The operator thus receives an optical or acoustic warning signal if the defined contact pressure is not applied to the sample. Preferably, the control device includes two sensors, one positioned at the minimum required deflection and the other at the maximum permissible deflection.

[0030] In preferred embodiments, the lid includes a downwardly projecting linear guide on its underside, tensioned by a pressure spring, for the linear guidance of the pressure plate. This linear guide allows the pressure plate to be displaced relative to the lid against the force of the pressure spring. The linear guide is preferably vertically oriented when the lid is in the closed position. The linear guide is preferably arranged centrally on the lid. The lid supports the pressure plate via the linear guide.

[0031] In preferred embodiments, the linear guide comprises a guide sleeve and a guide rod that is slidable within the guide sleeve. Either the guide sleeve is attached to the cover, while the guide rod is attached to the pressure plate, or the guide rod is attached to the cover, while the guide sleeve is attached to the pressure plate. The guide rod is preferably rotatably mounted within the guide sleeve to allow the pressure plate to rotate relative to the cover. The pressure spring is preferably designed as a coil spring in the form of a compression spring, which sits on the guide sleeve and the guide rod and is clamped between the cover and the pressure plate.

[0032] The pressure plate preferably has the shape of a plate, a flat cylinder, or a flat cone. The pressure plate has an extension in its main plane that preferably fits snugly into the interior of the sample container with some clearance. The pressure plate has a diameter that is preferably between 50 mm and 200 mm.

[0033] The analytical instrument according to the invention is used for the spectral analysis of a sample. It comprises a base body and a sample container to be arranged in the base body. The analytical instrument also includes the closure unit according to the invention. Preferably, the analytical instrument has one of the described preferred embodiments of the closure unit according to the invention. Preferably, the analytical instrument also has features that are specified in connection with the closure unit according to the invention. Further advantages, details, and developments of the invention will become apparent from the following description of preferred embodiments of the invention, with reference to the drawing. The drawing shows:

[0034] Fig. 1: a perspective view of a preferred embodiment of an analytical instrument according to the invention;

[0035] Fig. 2: a locking unit shown in Fig. 1 in a first position in a sectional view in detail;

[0036] Fig. 3: the locking unit shown in Fig. 2 in a second position in a detailed sectional view;

[0037] Fig. 4: a detailed exploded view of a guide unit as shown in Fig. 2;

[0038] Fig. 5: a pressure plate with a linear guide shown in Fig. 1 in detail in a first perspective view;

[0039] Fig. 6: the pressure plate with linear guide shown in Fig. 5 in detail in a side view;

[0040] Fig. 7: the pressure plate with linear guide shown in Fig. 5 in detail in a second perspective view;

[0041] Fig. 8: a lid shown in Fig. 1 with the pressure plate in a side view;

[0042] Fig. 9: the lid with the pressure plate shown in Fig. 8 in a first perspective view; and Fig. 10: the lid with the pressure plate shown in Fig. 8 in a second perspective view.

[0043] Fig. 1 shows a perspective view of a preferred embodiment of an analytical instrument according to the invention for the spectral analysis of a sample of an agricultural product, animal feed, or foodstuff. The analytical instrument is designed as a mobile tabletop device and comprises a base unit 01 with three feet 02 for placing the analytical instrument on a surface (not shown). The base unit 01 also has two carrying handles 03. For performing the spectral analysis, a light source (not shown), a spectrometer (not shown), and control and evaluation electronics (not shown) are arranged in the base unit 01.

[0044] The instrument base 01 has a sample container receptacle 04 for receiving a sample container 06. The sample container receptacle 04 is designed to transmit a torque from the instrument base 01 to the sample container 06 via a magnetic field in order to rotate it. For this purpose, the sample container receptacle 04 includes several electromagnets (not shown) which act on permanent magnets (not shown) on the sample container 06. A sample (not shown) to be spectrally analyzed is to be placed in the sample container 06.

[0045] The analyzer also includes a preferred

[0046] This is an embodiment of a closure unit 08 according to the invention for closing the analyzer with the sample container 06 (not shown) arranged therein, in order to prevent electromagnetic radiation, such as UV radiation, light, and IR radiation, from outside the analyzer from reaching the sample (not shown) and distorting the spectral analysis. The closure unit 08 comprises a hood-shaped cover 09, a pressure plate 11, a pivot bearing 12, and a guide unit 14. The pressure plate 11 is attached to the cover 09 via a linear guide 16, so that the pressure plate 11 is linearly displaceable relative to the cover 09. A pressure spring 17 is mounted on the linear guide 16, which pushes the pressure plate 11 away from the cover 09.

[0047] Fig. 2 shows the closure unit 08 shown in Fig. 1 in a first position in a detailed sectional view. In this first position, the cover 09 is linearly moved to its lowest position in the guide unit 14, so that the cover 09 closes the analyzer (shown in Fig. 1). The guide unit 14 comprises two guide rails 19 in which guide carriages 21 slide. A retaining plate 22, which supports the pivot bearing 12, is attached to the guide carriages 21. A locking bolt 23 (shown in Fig. 3) is also attached to the retaining plate 22, which, in the lowermost position of the cover 09 shown, is pushed into a locking bolt receptacle 24, thus locking the guide unit 14 and consequently the cover 09 in its lowest position. The guide unit 14 also includes a gas spring 26 for lifting the cover 09 with the pressure plate 11 attached to it.

[0048] A stop bolt 28 runs in a guide (not shown) to limit the pivoting movement of the cover 09 in the pivot bearing 12. Furthermore, the pivot bearing 12 is locked when the cover 09 has not moved to its uppermost position in the guide unit 14. The linear guide 16 comprises a guide sleeve 29 attached to the cover 09 and a guide rod 31, which is slidable in the guide sleeve 29 and to which the pressure plate 11 is attached.

[0049] The cover 09 is connected to the swivel bearing 12 via a retaining rod 33.

[0050] Fig. 3 shows the closure unit 08 shown in Fig. 2 in a second position in a detailed sectional view. In this second position, the cover 09 has moved linearly to its uppermost position in the guide unit 14, so that the cover 09 no longer closes the analyzer (shown in Fig. 1). The pivot bearing 12 is not locked in this uppermost position, so that the cover 09 can be pivoted open in the pivot bearing 12 to expose the sample container 06 (shown in Fig. 1). To move the cover 09 upwards in the guide unit 14, the locking mechanism of the locking bolt 23 in the locking bolt receptacle 24 had to be released, whereupon the cover 09, with the pressure plate 11 attached to it, was lifted by the gas spring 26.

[0051] Fig. 4 shows the guide unit 14 shown in Fig. 2 in an exploded view in detail. In this view, the pivot bearing 12, the guide rails 19, the guide carriages 21, the retaining plate 22, the locking bolt 23, the locking bolt receptacle 24 and the gas spring 26 can be seen in particular.

[0052] Fig. 5 shows the pressure plate 11 with the linear guide 16 shown in Fig. 1 in detail in a first perspective view. In this view, the arrangement of the guide sleeve 29, the guide rod 31, and the pressure spring 17 can be seen. Fig. 6 shows the pressure plate 11 with the linear guide 16 shown in Fig. 5 in detail in a side view. In this view, the arrangement of the guide sleeve 29, the guide rod 31, and the pressure spring 17 can again be seen.

[0053] Fig. 7 shows the pressure plate 11 with the linear guide 16 shown in Fig. 5 in detail in a second perspective view, with the guide rod 31 being pulled out of the guide sleeve 29 for illustration.

[0054] Fig. 8 shows the cover 09 with the pressure plate 11 shown in Fig. 1 in detail in a side view. In this view it can be seen in particular that the hood shape of the cover 03 is extended in a shield-like manner.

[0055] Fig. 9 shows the cover 09 with the pressure plate 11 shown in Fig. 8 in detail in a first perspective view. In this view, the central arrangement of the pressure plate 11 on the cover 03 can be seen in particular.

[0056] Fig. 10 shows the cover 09 with the pressure plate 11 shown in Fig. 8 in a second perspective view, with the guide sleeve 29 removed from the cover 09 for illustration.

[0057] character list

[0058] 01 Device base

[0059] 02 feet

[0060] 03 Carrying handle

[0061] 04 Sample container intake

[0062] 05

[0063] 06 Sample containers

[0064] 07

[0065] 08 Locking unit

[0066] 09 lids

[0067] 10

[0068] 11 Pressure plate

[0069] 12 Swivel bearing

[0070] 13

[0071] 14 Command Unit

[0072] 15

[0073] 16 linear guides

[0074] 17 pressure spring

[0075] 18

[0076] 19 Guide rail

[0077] 20

[0078] 21 guide carriages

[0079] 22 Mounting plate

[0080] 23 locking bolts

[0081] 24 locking bolt receptacles

[0082] 25

[0083] 26 Gas spring

[0084] 27

[0085] 28 stop bolts

[0086] 29 Guide sleeve

[0087] 30

[0088] 31 Guide rod 32

[0089] 33 Handrail

Claims

Patent claims 1. Closure unit (08) for an analyzer for the spectral analysis of a sample; comprising the following components: - a swiveling lid (09) for covering a sample container (06) of the analyzer; and - a pressure plate (11) for exerting a pressure on a sample located in the sample container (06), wherein the pressure plate (11) is arranged under the lid (09) and held on the lid (09), wherein the pressure plate (11) is displaceable against a force of a pressure spring (17) relative to the lid (09).

2. Closure unit (08) according to claim 1, characterized in that the sample container (06) has a bottom which is permeable to radiation generated by a radiation source of the analyzer and to radiation reflected by the sample.

3. Closure unit (08) according to claim 1 or 2, characterized in that the pressing pressure exerted by the pressure plate (11) acts from above on the sample and compresses the sample.

4. Closure unit (08) according to one of claims 1 to 3, characterized in that, when the lid (09) is closed, the pressure plate (11) is located in the sample container (06) and exerts a pressure on the sample caused by the pressure spring (17).

5. Closure unit (08) according to one of claims 1 to 4, characterized in that the pressure plate (11) is rotatably mounted about an axis relative to the cover (09).

6. Closure unit (08) according to one of claims 1 to 5, characterized in that it further comprises a pivot bearing (12) for the lid (09) in which the lid (09) can be pivoted from a covering position covering the sample container (06) to an uncovering position revealing the sample container (06) and vice versa.

7. Closure unit (08) according to claim 6, characterized in that it further comprises a guide unit (14) for guiding the pivot bearing (12) relative to a device base (01) of the analyzer, in which the pivot bearing (12) is displaceable relative to the device base (01) in order to displace the lid (09) in the covering position towards and away from the sample container (06) arranged in the device base (01).

8. Locking unit (08) according to claim 7, characterized in that the pivot bearing (12) is locked to fix the cover (09) in the cover position when the pivot bearing (12) in the guide unit (14) is moved to a position below an upper position of the pivot bearing (12).

9. Closure unit (08) according to claim 7 or 8, characterized in that it further comprises a locking mechanism (23, 24) for locking the pivot bearing (12) displaced to a lower position in the guide unit (14), wherein the cover (09) closes the analyzer when the pivot bearing (12) is in the lower position.

10. Locking unit (08) according to one of claims 7 to 9, characterized in that the guide unit (14) comprises a lifting spring (26) for raising the pivot bearing (12) with the cover (09) mounted therein.

11. Locking unit (08) according to one of claims 7 to 10, characterized in that the guide unit (14) is telescopically designed and comprises at least two telescopically slidable tube sections.

12. Closure unit (08) according to one of claims 1 to 11, characterized in that it further comprises a control device with which it is possible to check whether the pressure spring (17) is deflected between a minimum necessary deflection and a maximum permissible deflection when the pressure plate (11) is pressed onto the sample to exert a pressure.

13. Closure unit (08) according to one of claims 1 to 12, characterized in that the cover (09) comprises on an underside of the cover (09) a downwardly projecting linear guide (29, 31) tensioned by the pressure spring (17) for the linear guidance of the pressure plate (11).

14. Locking unit (08) according to claim 13, characterized in that the linear guide (29, 31) comprises a guide sleeve (29) and a guide rod (31) slidable in the guide sleeve (29), wherein the guide sleeve (29) is attached to the cover (09) and the guide rod (31) is attached to the pressure plate (11), or the guide rod (31) is attached to the cover (09) and the guide sleeve (29) is attached to the pressure plate (11).

15. Analytical device for the spectral analysis of a sample, comprising a device body (01) and a sample container (06) to be arranged in the device body (01) as well as a closure unit (08) according to one of claims 1 to 14.

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