Portable soil sampling and screening device for mining area environment investigation
By designing a portable soil sampling and screening device, using the combined structure of reamers and rotary knives, the problems of soil particle density change and sample breakage in moraine sampling in mining areas are solved, and efficient and accurate soil sampling and analysis are achieved.
Patent Information
- Application Number
- CN202510096927.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-03-25
AI Technical Summary
When sampling moraines in mining areas, the prior art has problems such as changing soil particle density, sample crushing and complex sampling processes during the sampling process, which affects the accuracy of subsequent analysis.
A portable soil sampling and screening device is designed, using a combined structure of a reamer and a rotary knife. By pre-cleaning ground debris, excessive extrusion of soil is reduced, and the soil is separated and polymerized by sampling hoods are used to simplify the sampling process.
It improves the grabability of soil samples and the accuracy of test data, simplifies the sampling process, avoids soil breakage and oversqueezing, and is especially suitable for water-wet soils.
Smart Images
Figure CN119688370A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of soil sampling, in particular to a portable soil sampling and screening device for mining area environmental investigation. Background Art
[0002] The environmental investigation of mining areas mainly includes the detection of soil structure and soil composition. When the soil is currently tested, soil sampling is inevitable. There is a kind of soil with complex composition in the mining area. During the glacial accumulation process, the debris carried and transported is composed of deposits, also known as glacial sediments. Its physical characteristics are loose and contain a lot of debris, which has certain mining value.
[0003] When sampling moraine in a mining area, a series of problems may be encountered, which are mainly due to the physical properties of moraine. Moraine is transported and accumulated by glaciers, and its particle sizes are mixed and arranged in no directional manner. If the natural collapse method is used for mining, the interior of the stratum will be hollowed out, which will inevitably cause the surface land to sink and collapse. Therefore, the sampling methods in the prior art include soil drilling method, ring knife method, etc., but the problem is that the existing sampling method is to drive a drill bit or a ring knife into the soil by applying pressure, but the drill bit or the ring knife must exert a certain pressure on the land, and the moraine soil samples are often loose. In the process of excessive squeezing, the density of the particles used for sampling in the soil will inevitably change, and the ring knife sampling process itself is very troublesome. It is necessary to repeatedly clean the soil around the ring knife by hand before and after the ring knife is driven in, which is also easy to cause the sample to break during the sampling process, which may affect the accuracy of subsequent analysis. For this reason, we propose a portable soil sampling and screening device for mining area environmental investigation. Summary of the invention
[0004] The object of the present invention is to provide a portable soil sampling and screening device for mining area environmental investigation to solve the problems raised in the above-mentioned background technology.
[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a portable soil sampling and screening device for mining environment investigation, comprising a grip tube, a guide ring is slidably connected to the bottom of the grip tube, a reamer is fixedly connected to the outside of the guide ring, a fixed plate is fixedly connected to the middle part of the grip tube, a slide rod is slidably connected to the inner ring of the fixed plate, a shell is fixedly connected to the top of the grip tube, a center rod is suspended on the top of the shell, a handle is rotatably installed on the top of the center rod, a limit strip is fixedly installed on the top of the center rod near the handle, a slide rod is fixedly connected to the bottom of the center rod, a pair of extension rods are fixedly connected to the slide rod, a connecting piece is fixedly connected to the bottom of the extension rod, a rotary cutter is fixedly installed on the bottom of the slide rod, a stabilizing rod is slidably connected to the connecting piece, a connecting key is fixedly connected to the bottom of the stabilizing rod, the bottom of the stabilizing rod is connected to the reamer through the connecting key, and a pair of detachable sampling covers are arranged between the slide rod and the rotary cutter.
[0006] Preferably, a second limit plate is fixedly connected to the middle of the center rod, a spring is fixedly connected to the top of the second limit plate, a first limit plate is connected to the top of the spring, the first limit plate and the outer shell are fixedly connected together, a fixing plate is fixedly installed in the middle of the grip tube, and the center rod and the fixing plate are slidably connected.
[0007] Preferably, the center rod is fixedly connected to a connecting strip near the top of the connecting strip, and the connecting strip is fixedly connected to a low-torque gear.
[0008] Preferably, the top of the outer shell is rotatably connected to a second gear ring, the top of the second gear ring is fixedly connected to a plurality of connecting plates that are equidistantly distributed, the common top of the plurality of connecting plates is fixedly connected to a first gear ring, the first gear ring and the outer shell are rotatably connected together, a second motor is fixedly connected inside the outer shell, a gear is sleeved on the output shaft of the second motor, and when the connecting bar drives the low-torque gear to rise, the low-torque gear and the second gear ring engage.
[0009] Preferably, a mounting plate is fixedly connected to the top of the shell, a screw rod is rotatably connected to the mounting plate, one end of the screw rod is fixedly connected to a turntable, the other end of the screw rod is threadedly connected to a block, one end of the mounting plate is fixedly connected to a guide rod, and the screw rod and the guide rod are slidably connected together.
[0010] Preferably, both upper and lower ends of the sampling cover are in an open state, and the inside thereof is anti-slip treated.
[0011] Preferably, the reamer and the rotary cutter are both electroplated, and the reamer is made of a set of connecting rings and annular cutting rods installed below the guide ring.
[0012] Preferably, the interior of the stabilizing rod is slidably connected to an insertion rod, the top of the insertion rod is fixedly connected to a magnetic ball, the side of the stabilizing rod is rotatably connected to a plurality of baffles, each of the baffles facing the insertion rod is fixedly mounted with a magnet, and the magnet and the magnetic ball have opposite poles and repel each other.
[0013] Preferably, a screening box is slidably connected to the outside of the shell, a center plate is fixedly connected to the middle of the inside of the screening box, a sieve plate is fixedly installed on the bottom of the screening box, a first motor is fixedly installed on the outside of the shell near the bottom of the sieve plate, a transition gear is sleeved on the output shaft of the first motor, a rack is fixedly installed on the bottom of the sieve plate, the rack and the transition gear are meshed, and a portable spectrometer is fixedly connected to both sides of the screening box.
[0014] Preferably, the portable spectrometer material is made of transparent intersections, and the central plate divides the interior of the screening box into two identical areas of equal volume to each sampling cover.
[0015] Compared with the prior art, the present invention has the following beneficial effects: The center rod in the present invention rotates, so that the center rod drives the sliding rod to rotate, the sliding rod rotates and drives the extension rod to rotate, the extension rod rotates and drives the connecting piece to rotate, so that the connecting piece drives the stabilizing rod to rotate, and at this time, the rotary cutter has long been away from the ground, so there is no interference with the ground, so that the reamer is independently vertical on the ground, so at this time, the debris on the ground can be cleaned in advance by driving the reamer, and then the rotation of the first motor is stopped, and then the grip tube is manually held and pressed down with force, so that the reamer descends to the inside of the surface layer of the ground, and in the process of the reamer descending to the inside of the surface layer of the ground, the rotary cutter and the top of the ground are re-attached, and the process of executing the reamer descending to the inside of the surface layer of the ground is conducive to pre-loosening the soil in the sampling area, and the soil remains in place, thereby improving the graspability of the sample; The sampling cover is installed between the reamer and the stabilizer bar. When the soil enters the soil, it will be separated on the inside and outside of each sampling cover. Since the soil at the bottom of the rotary cutter is relatively close, the soil will enter each sampling cover from the bottom of the sampling cover, allowing the soil to be aggregated together again. Then each sampling cover can be taken manually by squatting down, making the sampling process simple and convenient, and will not cause excessive squeezing and damage to the soil, especially for water-wet soils, which improves the accuracy of test data. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the overall internal structure of the present invention; Figure 3 It is a schematic diagram of another reamer structure of the present invention; Figure 4 For the present invention Figure 2 A schematic diagram of the enlarged structure at B in the middle; Figure 5 It is a schematic diagram of the structure of the stabilizer bar of the present invention; Figure 6 This is a schematic diagram of the structure of the screening and rotating device of the present invention; Figure 7 This is a schematic diagram of the structure of the first gear ring and the second gear ring of the present invention; Figure 8 This is a schematic diagram of the sampling cover structure of the present invention; Fig. 9 It is a schematic diagram of the structure of the present invention for locking the center rod; Fig.10 For the present invention Figure 1 A schematic diagram of the enlarged structure at A in the middle; Fig.11 Schematic diagram of the sampling process of the present invention.
[0017] In the figure: 1-grip tube; 2-reamer; 201-guide ring; 3-housing; 4-handle; 5-screening box; 501-center plate; 6-portable spectrometer; 7-first limit plate; 8-spring; 9-center rod; 10-connecting strip; 11-sampling cover; 12-rotating knife; 13-second limit plate; 14-fixing plate; 15-slide rod; 16-extension rod; 17-connecting plate; 1701-stabilizing rod; 18-connecting key; 19-baffle; 20-magnet; 21-magnetic ball; 22-rack; 23-first motor; 24-first gear ring; 25-connecting plate; 26-second gear ring; 27-second motor; 28-screw; 29-mounting plate; 30-guide rod; 31-block; 32-turntable; 33-limiting strip. DETAILED DESCRIPTION
[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0019] See also Figure 1-11The present invention provides a technical solution: a portable soil sampling device for mining area environmental investigation, comprising a grip tube 1, a guide ring 201 is slidably connected to the bottom of the grip tube 1, a reamer 2 is fixedly connected to the outside of the guide ring 201, a fixed plate 14 is fixedly connected to the middle of the grip tube 1, a slide bar 15 is slidably connected to the inner ring of the fixed plate 14, a housing 3 is fixedly connected to the top of the grip tube 1, a center rod 9 is suspended on the top of the housing 3, a handle 4 is rotatably installed on the top of the center rod 9, and the top of the center rod 9 is fixed near the handle 4. A limit strip 33 is fixedly installed, a slide bar 15 is fixedly connected to the bottom of the middle rod 9, a pair of extension rods 16 are fixedly connected to the slide bar 15, a connecting piece 17 is fixedly connected to the bottom of the extension rod 16, a rotary cutter 12 is fixedly installed at the bottom of the slide bar 15, a stabilizing rod 1701 is slidably connected to the connecting piece 17, a connecting key 18 is fixedly connected to the bottom of the stabilizing rod 1701, and the bottom of the stabilizing rod 1701 is connected to the reamer 2 through the connecting key 18, and a pair of detachable sampling rods are arranged between the slide bar 15 and the rotary cutter 12 The cover 11; the middle of the center rod 9 is fixedly connected with a second limit plate 13, the top of the second limit plate 13 is fixedly connected with a spring 8, the top of the spring 8 is connected with a first limit plate 7, the first limit plate 7 and the shell 3 are fixedly connected together, a fixing plate 14 is fixedly installed in the middle of the grip tube 1, and the center rod 9 and the fixing plate 14 are slidably connected; the center rod 9 is fixedly connected with a connecting strip 10 near the top of the connecting strip 10, and the connecting strip 10 is fixedly connected with a low-torque gear; the top of the shell 3 is rotatably connected with The second gear ring 26 has a plurality of connecting plates 25 fixedly connected to the top of the second gear ring 26 at equal intervals, and the common top of the plurality of connecting plates 25 is fixedly connected to the first gear ring 24, and the first gear ring 24 is rotatably connected to the housing 3, and the second motor 27 is fixedly connected to the inside of the housing 3, and a gear is sleeved on the output shaft of the second motor 27, and when the connecting strip 10 drives the low-torque gear to rise, the low-torque gear and the second gear ring 26 are meshed; wherein the shape of the reamer 2 is not unique, and it can be selected according to actual conditions, such as the attached Figure 2 shown.
[0020] First, the grip tube 1 is manually held to erect the entire device on the ground, and then the handle 4 is controlled by the other hand and lifted upward, so that the handle 4 drives the center rod 9 to rise. During the rising process, the center rod 9 drives the second limit plate 13 to rise. During the rising process of the second limit plate 13, the spring 8 is compressed, so that the bottom of the center rod 9 drives the sliding rod 15 to rise, and its top drives the connecting bar 10 to rise. When the gear at one end of the connecting bar 10 contacts the second gear ring 26, the control of the handle 4 is manually stopped, and the turntable is turned by hand. 32, let the turntable 32 drive the screw rod 28 to rotate on the mounting plate 29, so that the block 31 is located on the guide rod 30 and moves toward the limit bar 33 under the rotation of the screw rod 28, and finally the limit bar 33 and the block 31 are matched, so that the middle rod 9 is raised and stays at a certain position. In this process, the slide bar 15 drives the extension rod 16 to rise, and the slide bar 15 drives the rotary cutter 12 to rise at the same time. The stabilizing rod 1701 has the effect of gravity, and the bottom of the stabilizing rod 1701 is in contact with the ground, and can always maintain connection with the middle part of the reamer 2, and the rotary cutter 12 rises. Afterwards, the whole is manually held to take samples at the sampling point. When sampling, the first motor 23 is turned on first. The rotation of the first motor 23 causes the gear to rotate. The rotation of the gear causes the first gear ring 24 to rotate. The rotation of the first gear ring 24 drives the second gear ring 26 to rotate, so that the center rod 9 rotates, and then the center rod 9 drives the slide rod 15 to rotate. The rotation of the slide rod 15 drives the extension rod 16 to rotate. The rotation of the extension rod 16 drives the connecting piece 17 to rotate, so that the connecting piece 17 drives the stabilizing rod 1701 to rotate. At this time, the rotary cutter 12 has already been far away. It is off the ground, so there is no interference with the ground, so that the reamer 2 is independently vertical on the ground. Therefore, at this time, the debris on the ground can be cleaned up in advance by driving the reamer 2, and then the rotation of the first motor 23 is stopped, and then the handle 1 is manually held and pressed down hard to make the reamer 2 descend to the inside of the surface layer of the ground. In the process of the reamer 2 descending to the inside of the surface layer of the ground, the rotary cutter 12 and the top of the ground are re-fitted. The process of executing the reamer 2 descending to the inside of the surface layer of the ground is conducive to loosening the soil in the sampling area in advance, and the soil is retained in place, thereby improving the graspability of the sample.
[0021] The top of the housing 3 is fixedly connected with a mounting plate 29, and the mounting plate 29 is rotatably connected with a screw rod 28. One end of the screw rod 28 is fixedly connected with a turntable 32, and the other end of the screw rod 28 is threadedly connected with a clamping block 31. One end of the mounting plate 29 is fixedly connected with a guide rod 30, and the screw rod 28 and the guide rod 30 are slidably connected together. Then, the first motor 23 is turned on again to rotate, so that the reamer 2 rotates and the reamer 2 cuts the ground. Fig.11As shown, the sampling method adopts the existing matrix sampling, which is convenient for obtaining the accuracy of the data. Then, the turntable 32 is manually rotated, and the turntable 32 rotates to make the screw rod 28 flip over, so as to separate the block 31 and the limit bar 33 and reset the spring 8. After the spring 8 is reset, the soil will stop rotating after the rotary cutter 12 stops rotating. The rotary cutter 12 is driven by the spring 8 to drop, and the soil will slowly enter between the rotary cutter 12 and the stabilizing rod 1701. In the process of entering the soil, since the sampling cover 11 is installed between the reamer 2 and the stabilizing rod 1701, the soil will be separated from the inside and outside of each sampling cover 11 when entering the soil. Since the soil at the bottom of the rotary cutter 12 is relatively close, the soil will enter each sampling cover 11 from the bottom of the sampling cover 11, so that the soil is aggregated again, and then each sampling cover 11 can be taken by squatting manually, so that the sampling process is simple and convenient, and will not cause excessive squeezing and damage to the soil, especially for water-wet soil, the accuracy of the test data is improved.
[0022] The upper and lower ends of the sampling cover 11 are both in an open state, and the interior thereof is treated with anti-slip treatment; the reamer 2 and the rotary cutter 12 are both electroplated, and the reamer 2 is made of a set of connecting rings and ring cutting rods installed under the guide ring 201. It is worth mentioning that when sampling, the bottom of the sampling cover 11 and the top of the rotary knife 12 are in an overlapping state. When the rotary knife 12 and the sampling cover 11 are separated, the soil at the bottom of the sampling cover 11 is cut off with the top of the rotary knife 12 as a node, while the top of the sampling cover 11 will not overflow due to the action of the connecting piece 17 and the extension rod 16. At the same time, the soil itself has a certain amount of moisture, which gives it a certain viscosity, so that the sampling cover 11 will not fall down when people take it.
[0023] Furthermore, the stabilizing rod 1701 is slidably connected to an insertion rod, a magnetic ball 21 is fixedly connected to the top of the insertion rod, and a plurality of baffles 19 are rotatably connected to the side of the stabilizing rod 1701, and a magnet 20 is fixedly installed on the side of each baffle 19 facing the insertion rod, and the magnet 20 and the magnetic ball 21 have opposite magnetic poles and repel each other; when the device is picked up as a whole, the magnetic ball 21 drops due to gravity, so that the magnetic ball 21 and the magnet 20 come into contact, driving the magnet 20 to move radially toward the stabilizing rod 1701, so that the baffle 19 opens, and one end of the baffle 19 comes into contact with the inside of the rotary cutter 12, allowing most of the soil to come into contact with the baffle 19. The baffle 19 retains the soil inside the stabilizing rod 1701, making it convenient to sample the soil multiple times for testing different data, such as the content and structure of the substances inside the soil. The baffle 19 can be reset manually.
[0024] Furthermore, a screening box 5 is slidably connected to the outside of the shell 3, a center plate 501 is fixedly connected to the middle of the inside of the screening box 5, a sieve plate is fixedly installed at the bottom of the screening box 5, a first motor 23 is fixedly installed on the outside of the shell 3 near the bottom of the sieve plate, a transition gear is sleeved on the output shaft of the first motor 23, a rack 22 is fixedly installed at the bottom of the sieve plate, the rack 22 is meshed with the transition gear, and a portable spectrometer 6 is fixedly connected to both sides of the screening box 5; the portable spectrometer 6 is made of transparent intersection, and the center plate 501 divides the inside of the screening box 5 into two identical areas of equal volume to each sampling cover 11; when the soil needs to be tested, the soil sample can be screened manually, which can be done by manually taking Take the sampling cover 11 that has been sampled and put it into the screening box 5, turn on the second motor 27 to rotate, and the second motor 27 drives the rack 22 to move on the transition gear, so that the screening box 5 moves, which makes the screening box 5 produce a vibration effect, and some smaller particles inside the soil are screened out, retaining the physical structure of large particles, and then turn on the portable spectrometer 6 to test the substances inside each screening box 5, measure the proportion of moraine and other substances, and then compare the values generated between the two sampling covers 11, so as to accurately test the numerical size of the sample in the hole area, and then pour out all the soil retained in the stabilizing rod 1701, so as to test the water content of the area, and finally manually perform multi-point sampling on the mining area.
[0025] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.
[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A portable soil sampling device for mining area environmental investigation, comprising a grip tube (1), characterized in that: The bottom of the grip tube (1) is slidably connected to a guide ring (201), the outside of the guide ring (201) is fixedly connected to a reamer (2), the middle of the grip tube (1) is fixedly connected to a fixing plate (14), the inner ring of the fixing plate (14) is slidably connected to a sliding rod (15), the top of the grip tube (1) is fixedly connected to a housing (3), a center rod (9) is suspended from the top of the housing (3), a handle (4) is rotatably mounted on the top of the center rod (9), a limit strip (33) is fixedly mounted on the top of the center rod (9) near the handle (4), and the bottom of the center rod (9) is fixedly A slide rod (15) is connected, the slide rod (15) is fixedly connected to a pair of extension rods (16), the bottom of the extension rod (16) is fixedly connected to a connecting plate (17), the bottom of the slide rod (15) is fixedly installed with a rotary cutter (12), the connecting plate (17) is slidably connected to a stabilizing rod (1701), the bottom of the stabilizing rod (1701) is fixedly connected to a connecting key (18), the bottom of the stabilizing rod (1701) is connected to the reamer (2) via the connecting key (18), and a pair of detachable sampling covers (11) are provided between the slide rod (15) and the rotary cutter (12).
2. A portable soil sampling device for mining area environmental investigation according to claim 1, characterized in that: A second limit plate (13) is fixedly connected to the middle of the center rod (9), a spring (8) is fixedly connected to the top of the second limit plate (13), a first limit plate (7) is connected to the top of the spring (8), the first limit plate (7) and the housing (3) are fixedly connected together, a fixing plate (14) is fixedly installed in the middle of the grip tube (1), and the center rod (9) and the fixing plate (14) are slidably connected.
3. The portable soil sampling device for mining area environmental investigation according to claim 2 is characterized in that: The center rod (9) is fixedly connected to a connecting strip (10) near the top of the connecting strip (10), and the connecting strip (10) is fixedly connected to a low-torque gear.
4. The portable soil sampling device for mining area environmental investigation according to claim 3 is characterized in that: The top of the housing (3) is rotatably connected to a second gear ring (26); a plurality of connection plates (25) are fixedly connected to the top of the second gear ring (26) at equal intervals; a first gear ring (24) is fixedly connected to the common top of the plurality of connection plates (25); the first gear ring (24) and the housing (3) are rotatably connected together; a second motor (27) is fixedly connected inside the housing (3); a gear is sleeved on the output shaft of the second motor (27); when the connection bar (10) drives the low-torque gear to rise, the low-torque gear and the second gear ring (26) mesh.
5. The portable soil sampling device for mining area environmental investigation according to claim 4 is characterized in that: A mounting plate (29) is fixedly connected to the top of the housing (3), a screw rod (28) is rotatably connected to the mounting plate (29), one end of the screw rod (28) is fixedly connected to a turntable (32), the other end of the screw rod (28) is threadedly connected to a clamping block (31), one end of the mounting plate (29) is fixedly connected to a guide rod (30), and the screw rod (28) and the guide rod (30) are slidably connected together.
6. The portable soil sampling device for mining area environmental investigation according to claim 1 is characterized in that: The upper and lower ends of the sampling cover (11) are both in an open state, and the interior thereof is subjected to anti-slip treatment.
7. The portable soil sampling device for mining area environmental investigation according to claim 1 is characterized in that: The reamer (2) and the rotary cutter (12) are both electroplated, and the reamer (2) is made of a group of connecting rings and annular cutting rods installed below the guide ring (201).
8. The portable soil sampling device for mining area environmental investigation according to claim 1 is characterized in that: The stabilizing rod (1701) is slidably connected to an insertion rod inside, the top of the insertion rod is fixedly connected to a magnetic ball (21), and the stabilizing rod (1701) is rotatably connected to a plurality of baffles (19) on the side, each baffle (19) is fixedly mounted with a magnet (20) on a side facing the insertion rod, and the magnet (20) and the magnetic ball (21) have opposite magnetic poles and repel each other.
9. The screening device used in portable soil sampling for mining area environmental investigation according to claim 1, characterized in that: The outer part of the housing (3) is slidably connected to a screening box (5), a center plate (501) is fixedly connected to the middle of the inner part of the screening box (5), a screening plate is fixedly installed at the bottom of the screening box (5), a first motor (23) is fixedly installed on the outer part of the housing (3) near the bottom of the screening plate, a transition gear is sleeved on the output shaft of the first motor (23), a rack (22) is fixedly installed at the bottom of the screening plate, the rack (22) is meshed with the transition gear, and a portable spectrometer (6) is fixedly connected to both sides of the screening box (5).
10. The portable soil screening device for mining area environmental investigation according to claim 9, characterized in that: The portable spectrometer (6) is made of a transparent material, and the middle plate (501) divides the interior of the screening box (5) into two identical areas of equal volume to each sampling cover (11).