A half-value layer automatic measuring device

Abstract

The application relates to a half-value layer automatic measuring device, which effectively solves the problems of inconvenient operation and low measuring precision in the existing half-value layer measuring process; the technical solution comprises the following steps: first, second and third rings are arranged on the coaxial shaft of a measuring frame, the first ring, the second ring and the third ring are rotationally installed on the measuring frame, a plurality of placing holes are equidistantly arranged on the circumferential wall of the first ring, the second ring and the third ring, and a limiting assembly is arranged in the placing hole, the first ring, the second ring and the third ring are respectively connected with driving assemblies, and a detector is arranged at the center position of the first ring; in the half-value layer measuring process, the staff does not need to replace (adjust) the aluminum sheet, the corresponding ring only needs to be controlled to rotate in the whole process, the half-value layer parameter of the X-ray source can be quickly measured, and the aluminum sheet at the outermost side can be cleaned to a certain extent, so that the floating dust accumulated on the surface of the aluminum sheet does not affect the measuring precision.

Description

Technical Field

[0001] This invention belongs to the field of half-value layer technology, and specifically relates to an automatic measurement device for half-value layers. Background Technology

[0002] Half-value layer measurement is a commonly used measurement method to determine the output quality and safety of an X-ray source. The half-value layer refers to the thickness of a certain material (usually aluminum) required for the X-ray intensity to decay to half of its initial value. When performing half-value layer measurement, X-rays emitted from the X-ray source are usually irradiated onto an aluminum sheet, and then the half-value layer is calculated by measuring the intensity of the X-rays after passing through the aluminum sheet.

[0003] When measuring the half-value layer, it is usually necessary for staff to frequently change aluminum sheets (of different thicknesses) so that the total thickness of the aluminum sheet through which X-rays pass meets the requirement that the intensity of X-rays detected by the detector is exactly half of the initial value. Because staff need to frequently adjust the aluminum sheet, the operation is cumbersome and inefficient. Moreover, the frequent adjustment of the aluminum sheet also increases the probability of staff being irradiated by the X-ray source, which is detrimental to the health of the staff.

[0004] In addition, if aluminum sheets are not stored properly when not in use, a layer of dust will accumulate on their surface. The dust accumulated on the surface of the aluminum sheets will have a certain impact on the attenuation of X-rays, causing certain deviations in the measurement results.

[0005] In view of the above, this application provides an automatic half-value layer measurement device to solve the above problems. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention provides an automatic half-value layer measurement device. During the half-value layer measurement process, there is no need for staff to replace (adjust) the aluminum sheet. The entire process only requires controlling the rotation of the corresponding ring to quickly measure the half-value layer parameters of the X-ray source. In addition, it can also clean the outermost aluminum sheet to a certain extent to prevent the dust accumulated on the surface of the aluminum sheet from affecting the measurement accuracy.

[0007] An automatic measurement device for half-value layers includes a measuring frame, characterized in that a first ring, a second ring, and a third ring are coaxially spaced on the measuring frame and the first ring, the second ring, and the third ring are rotatably mounted with respect to the measuring frame;

[0008] The first ring, the second ring, and the third ring are provided with a plurality of placement holes at equal intervals on their circumferential walls, and a limiting component is provided in the placement holes. A support ring is provided coaxially in the placement holes.

[0009] The first ring, the second ring, and the third ring are each connected to a drive assembly. A magnetic suction plate can be detachably installed on the side of the first ring away from the measuring frame.

[0010] A detector is located at the center of the first ring.

[0011] The beneficial effects of the above technical solution are as follows:

[0012] (1) In the process of measuring the half-value layer, this solution does not require staff to replace (adjust) the aluminum sheet. The whole process only requires controlling the corresponding ring to rotate, which can quickly and accurately measure the half-value layer parameters of the X-ray source.

[0013] (2) In this scheme, the aluminum sheet on the outermost side (placed on the first ring) can also be cleaned to a certain extent to prevent the dust accumulated on the surface of the aluminum sheet from affecting the measurement accuracy. Moreover, the dust removed will not contaminate the aluminum sheets on the second and third rings.

[0014] (3) In this scheme, the detector is located in the sealed space composed of the measuring frame, the first ring, the second ring, the third ring, and the magnetic plate. When the device is not in use, it can provide a better storage environment for the detector and several aluminum sheets on the second and third rings to prevent them from being contaminated by dust in the external environment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 This is a schematic diagram of the main view of the present invention after the magnetic chuck is removed;

[0017] Figure 3 This is a schematic diagram showing the positional relationship between the magnetic suction plate and the measuring frame after separation of the support ring in this invention.

[0018] Figure 4 This is a schematic diagram showing the positional relationship between the air cylinder, air chamber, mounting hole, and support ring of the present invention;

[0019] Figure 5 This is a schematic diagram of the internal structure of the first ring, second ring, and third ring of the present invention;

[0020] Figure 6 This is a schematic diagram showing the connection relationship between the piston, air cylinder, and air pipe of the present invention. Detailed Implementation

[0021] The foregoing and other technical contents, features and effects of the present invention are described in conjunction with the appendix below. Figures 1 to 6 As will be clearly shown in the detailed description of the embodiments, the structural contents mentioned in the following embodiments are all with reference to the accompanying drawings.

[0022] Example 1: This example provides an automatic measurement device for half-value layers, such as... Figure 1 As shown, including measuring frame 1, the improvement of this solution is as follows:

[0023] like Figure 2 As shown, a first ring 2, a second ring 3, and a third ring 4 are coaxially spaced on one side of the measuring frame 1, and the first ring 2, the second ring 3, and the third ring 4 are rotatably mounted to the measuring frame 1. That is, one side wall of the first ring 2, the second ring 3, and the third ring 4 is in rotatable contact with the measuring frame 1. Figure 5 As shown, several placement holes 5 are equidistantly spaced on the circumferential walls of the first ring 2, the second ring 3, and the third ring 4 (each ring can have 10 placement holes 5, thus allowing for the placement of ten aluminum sheets of different thicknesses). A support ring 6 is coaxially arranged inside the placement hole 5. Note: The aluminum sheets used in this scheme have different thicknesses, but the diameters of the aluminum sheets are the same, and the diameter of the aluminum sheets is between the inner diameter of the placement hole 5 and the inner diameter of the support ring 6 (the diameter of the aluminum sheets is slightly smaller than the inner diameter of the placement hole 5). This ensures that when the aluminum sheets are placed in the placement hole 5, they will not fall from the bottom of the placement hole 5 under the support of the support ring 6. In addition, a limiting component is provided inside the placement hole 5 to ensure that when several aluminum sheets rotate circumferentially with the corresponding rings, the aluminum sheets in the placement holes 5 in the lower half of the rings fall out of the placement holes 5. The first ring 2, the second ring 3, and the third ring 4 are respectively connected to a drive component, which can control the rotation of the first ring 2, the second ring 3, and the third ring 4 and the size of the rotation angle.

[0024] It is worth noting that this scheme has three rings: ring 2, ring 3, and ring 4. Therefore, the aluminum sheets on each ring have the same thickness. For example, ring 2 can hold aluminum sheets with a thickness of 12-21 (12, 13...21) mm, ring 3 can hold aluminum sheets with a thickness of 2-11 (2, 3...9) mm, and ring 4 can hold aluminum sheets with a thickness of 0.1-1 (0.1, 0.2...1) mm (the order of placing aluminum sheets on the same ring should satisfy the condition that the thickness should decrease or increase sequentially). By rotating different rings, the thickness of the aluminum sheet through which X-rays pass can be arbitrarily adjusted within the range of 0.1 mm to 21 mm, which helps to complete the experimental measurement process quickly and efficiently.

[0025] It is worth noting that the dimensions of the aluminum sheets on the first ring 2, the second ring 3, and the third ring 4 in this solution can be adjusted according to actual measurement requirements to achieve the desired measurement results.

[0026] A detector 8 is fixedly installed at the center of the first ring 2, the second ring 3, and the third ring 4, on the measuring frame 1. Figure 1 , 3As shown, a magnetic suction plate 7 is detachably installed on the side of the first ring 2, the second ring 3, and the third ring 4 away from the measuring frame 1 (the magnetic suction plate 7 is magnetically attracted to the side wall of the first ring 2). When the magnetic suction plate 7 is installed, the second ring 3, the third ring 4, and the detector 8 can be placed in a relatively sealed environment, which can better prevent dust from the external environment from contaminating them (when the device is not in use, it provides a relatively clean storage environment for the aluminum sheets on the second ring 3 and the third ring 4 and the detector 8). In this embodiment, the specific working process is as follows:

[0027] The staff first removed the magnetic plate 7, then placed aluminum sheets of different specifications into the mounting holes 5 on the corresponding rings, and then installed the magnetic plate 7 on the first ring 2 (so that the detector 8, the second ring 3, and the third ring 4 are in a relatively sealed environment). It was set that when the magnetic plate 7 was installed on the side wall of the first ring 2, the inner wall of the magnetic plate 7 did not contact the side walls of the second ring 3 and the third ring 4 (with a slight distance). This is because when the drive assembly drives the first ring 2 to rotate, the magnetic plate 7 rotates synchronously with the first ring 2. At this time, the second ring 3 and the third ring 4 do not rotate. Therefore, the side walls of the second ring 3 and the third ring 4 are set with a slight distance from the magnetic plate 7 to avoid friction between the magnetic plate 7 and the side walls of the second ring 3 and the third ring 4 when the magnetic plate 7 rotates with the first ring 2 (causing unnecessary wear).

[0028] The X-ray beam emitted from the X-ray source was then used to irradiate the area from top to bottom, such as... Figure 2 As shown, X-rays pass through the aluminum sheets on the first ring 2, the second ring 3, and the third ring 4 from top to bottom. During measurement, the operator only needs to control the rotation of the first ring 2, the second ring 3, and the third ring 4 through the drive component to adjust and combine the aluminum sheets of different thicknesses, so that the intensity of X-rays received by the detector 8 reaches the required range (i.e., the intensity of X-rays is reduced to half of the initial value).

[0029] Note: After the first ring 2 (second ring 3 or third ring 4) is adjusted into place, the following must be met: the selected aluminum sheet located in the mounting hole 5 on the first ring 2 (second ring 3 or third ring 4) is in position. Figure 2 The X-ray beam is positioned along its path and perpendicular to the X-ray beam (ensuring the X-rays can pass perpendicularly through the aluminum sheets on the first ring 2, second ring 3, and third ring 4 to guarantee the accuracy of the measurement data). Since there are 10 aluminum sheets on each ring, when the operator controls the rotation of the corresponding ring to adjust the thickness of the aluminum sheet, the drive assembly should rotate the first ring 2 (second ring 3 and third ring 4) 360 / 10° each time to determine whether further adjustment of the aluminum sheet thickness is needed.

[0030] Example 2, based on Example 1, such as Figure 4As shown, an air cavity 9 is provided inside the circumferential wall of the first ring 2 at a position corresponding to the placement hole 5. Several air holes 10 communicating with the air cavity 9 are provided on the side wall of the placement hole 5 (the air holes 10 are located on the side wall of the placement hole 5 away from the supporting ring 6). A gas assembly is provided on the inner circumferential wall of the first ring 2, and the gas assembly communicates with the air cavity 9. The specific implementation process of this embodiment is as follows:

[0031] When the device is not in use, several aluminum sheets on the first ring 2 are exposed. Therefore, a layer of dust may adhere to the surface of several aluminum sheets located in the mounting hole 5 of the first ring 2 (if the storage environment of the measuring device is not good). However, since the second ring 3 and the third ring 4 are inside, it is difficult for dust to penetrate into them (because the diameter of the aluminum sheet and the inner diameter of the mounting hole 5 are not much different, when the aluminum sheet is placed in the mounting hole 5, it almost seals the mounting hole 5, thereby preventing dust from the external environment from penetrating into the internal environment of the first ring 2), thus keeping it in a relatively clean state.

[0032] When using this measuring device, in order to minimize the impact of floating dust on the surface of the aluminum sheet on the measurement results (when X-rays pass through the dust on the surface of the aluminum sheet, the particles in the dust will also interact with the X-rays, causing the energy of the X-rays to weaken, thus producing an attenuation effect, which will affect the measurement data of the half-value layer);

[0033] When the staff drives the first ring 2 to rotate 360 / 10° every time, a certain pressure of gas is delivered into the gas chamber 9 through the gas component and discharged outward through several air holes 10. The gas is quickly ejected through the air holes 10 and blown onto the surface of the aluminum sheet in the mounting hole 5, thereby blowing away the dust attached to its surface and minimizing the impact of dust on the measurement data.

[0034] Since the aluminum sheets on the second ring 3 and the third ring 4 are in a relatively sealed environment, when the surface of the aluminum sheet on the first ring 2 is cleaned, the dust blown off will not contaminate the aluminum sheets on the second ring 3 and the third ring 4, nor will it come into contact with the surface of the detector 8, thereby minimizing the impact of dust on the half-value layer measurement work.

[0035] Example 3, based on Example 2, such as Figure 6 As shown, the gas assembly includes an air cylinder 11 disposed within the circumferential wall of the first ring 2, with one end of the air cylinder 11 connected to the air chamber 9 via an air pipe 21 (e.g., Figure 6 The outline shown by the dashed line indicates the location of the air chamber 9 within the circumferential wall of the first ring 2. The other end of the air cylinder 11 communicates with the external environment via a discharge hole 23 located on the first ring 2. A piston 12, elastically connected to the air cylinder 11, is located inside the air cylinder 11, and a passive ball is located at one end of the piston 12 extending outwards from the air cylinder 11. Figure 1As shown, a trigger ball that cooperates with the passive ball is fixedly installed on the measuring frame 1 at a position offset from the center of the first ring 2, the second slide, and the third ring 4. The specific working process of this embodiment is as follows:

[0036] When the operator controls the first ring 2 to rotate relative to the measuring frame 1 (the drive assembly is set to drive the first ring 2, the second ring 3, and the third ring 4 to rotate along the same path), Figure 2 (Rotating counterclockwise as indicated by the middle arrow), whenever an aluminum sheet is about to rotate to a position perpendicular to the X-ray path (working position A), that is, before the aluminum sheet at position B is about to rotate to position A, the passive sphere and the trigger sphere work together to achieve the following: As the passive sphere rotates from position B to position A with the first ring 2, when the passive sphere touches the trigger sphere, it is obstructed by the trigger sphere and forced to move towards the side wall of the first ring 2. Figure 6 As shown, this synchronously drives the piston 12 to move towards the discharge port 23 within the air cylinder 11. At this time, outside air enters the air cylinder 11 through several air holes 10, air chambers 9, and air pipes 21, while the air originally located in the air cylinder 11 is discharged outward through the discharge port 23. The drive assembly is set to drive the first ring 2 to rotate at a relatively slow speed (at this time, the piston 12 also moves at a slow speed within the air cylinder 11, so that when the piston 12 moves to its limit displacement within the air cylinder 11 (at this time, the passive ball, under the resistance of the trigger ball, ... It also moves to the maximum distance, at which point the plane side of the passive hemisphere 13 and the plane side of the trigger hemisphere 14 are exactly parallel. As the first ring 2 continues to rotate, the passive hemisphere 13 and the trigger hemisphere 14 no longer contact each other, so that the piston 12 moves rapidly toward the initial position under the action of the spring connected to it. During the rapid movement of the piston 12, the gas in the air cylinder 11 is simultaneously driven to quickly enter the air chamber 9 and blow out from several air holes 10, thereby achieving the effect of cleaning the dust attached to the surface of the aluminum sheet.

[0037] Then, the first ring 2 continues to rotate at a certain angle, causing the aluminum sheet that was originally at position B to rotate to position A (working position).

[0038] Example 4, based on Example 1, such as Figure 4 As shown, the limiting component includes sliding holes 15 on both sides of the mounting holes 5 on the first ring 2, the second ring 3, and the third ring 4. Limiting plates 16 are slidably installed within the sliding holes 15 and elastically connected to them. Under the action of the connected springs, one end of the two mating limiting plates 16 extends into the corresponding mounting holes 5, thereby limiting the aluminum sheet placed within the mounting holes 5. In this embodiment, the process is as follows:

[0039] like Figure 5As shown, when the first ring 2, the second ring 3, and the third ring 4 rotate under the drive of the drive assembly, the aluminum sheet in the placement hole 5 located in the lower half of the first ring 2, the second ring 3, and the third ring 4 will abut against the two limiting plates 16 that cooperate with it due to gravity (at this time, the aluminum sheet no longer abuts against the supporting ring 6), thereby preventing it from falling out of the placement hole 5. As the first ring 2, the second ring 3, and the third ring 4 continue to rotate, so that when the aluminum sheet rotates from the lower half of the corresponding ring to the upper half, the aluminum sheet no longer abuts against the limiting plate 16 under its own gravity, but abuts against the supporting ring 6 again, thereby ensuring that the aluminum sheet located in the placement hole 5 will not fall out of the placement hole 5 during the rotation of the first ring 2, the second ring 3, and the third ring 4.

[0040] Example 5, based on Example 4, such as Figure 4 As shown in the enlarged view, a protrusion 17 is provided on the limiting plate 16 so that when the operator takes the aluminum sheet out of the placement hole 5, the protrusion 17 can better move the limiting plate 16 relative to the sliding hole 15 to realize the process of taking out and placing the aluminum sheet.

[0041] Example 6, based on Example 1, such as Figure 1 , 2 As shown, the drive assembly includes a gear system 18 evenly distributed along the circumference of the first ring 2, the second ring 3, and the third ring 4. Gears 19, meshing with the gear system 18, are rotatably mounted on the measuring frame 1. Each gear 19 is driven by a servo motor 20 fixedly mounted on the measuring frame 1 (a total of three servo motors 20 are provided). Figure 3 As shown, three servo motors 20 are fixedly installed on the side of the measuring frame 1 away from the first ring 2. The operator controls the rotation angle of the servo motors 20 through the microcontroller, thereby controlling the corresponding ring to rotate by a certain angle, so as to adjust the thickness of the aluminum sheet passing through the X-ray path.

[0042] Implementation 7, based on Example 1, such as Figure 1 , 2 As shown, in order to better control the path of X-rays, a guide hole 22 is provided at the upper end of the measuring frame 1, and the guide hole 22 and the central axis of the detector 8 are coincident. The operator only needs to adjust the positional relationship between the X-ray source and the guide hole 22 so that the X-rays emitted from the X-ray source can pass through the middle position of the guide hole 22, so that the detector 8 located inside the first ring 2, the second ring 3, and the third ring 4 can receive the X-rays.

[0043] The above description is only for illustrating the present invention and should be understood as not being limited to the above embodiments. Various modifications that conform to the spirit of the present invention are within the protection scope of the present invention.

Claims

1. An automatic measurement device for half-value layers, comprising a measuring frame (1), characterized in that, The measuring frame (1) is provided with a first ring (2), a second ring (3), and a third ring (4) at an interaxial distance, and the first ring (2), the second ring (3), and the third ring (4) are rotatably mounted on the measuring frame (1); The first ring (2), the second ring (3), and the third ring (4) are provided with a plurality of placement holes (5) at equal intervals on their circumferential walls, and a limiting component is provided in the placement holes (5). A support ring (6) is provided coaxially in the placement holes (5). The first ring (2), the second ring (3), and the third ring (4) are respectively connected to a drive assembly. A magnetic suction plate (7) is detachably installed on the side of the first ring (2) away from the measuring frame (1). A detector (8) is provided at the center of the first ring (2); The first ring (2) has an air chamber (9) at the position corresponding to the placement hole (5) in the circumferential wall, and the side wall of the placement hole (5) has a number of air holes (10) communicating with the air chamber (9). The air chamber (9) is connected to a gas component located in the circumferential wall of the first ring (2). The gas assembly includes a gas cylinder (11) disposed in the circumferential wall of the first ring (2), one end of the gas cylinder (11) is connected to the gas chamber (9), and the other end is connected to the outside. The air cylinder (11) is provided with a piston (12) elastically connected to it, and a passive hemisphere (13) is provided at one end of the piston (12) extending outward from the air cylinder (11). The measuring frame (1) is provided with a trigger hemisphere (14) corresponding to the passive hemisphere (13).

2. The automatic measurement device for half-value layers according to claim 1, characterized in that, The limiting component includes sliding holes (15) located on both sides of the placement hole (5) and coaxially arranged with the first ring (2), the second ring (3), and the third ring (4). A limiting plate (16) elastically connected to the sliding hole (15) is slidably installed in the sliding hole (15).

3. The automatic measurement device for half-value layers according to claim 2, characterized in that, The limiting plate (16) is provided with a protrusion (17).

4. The automatic measurement device for half-value layers according to claim 1, characterized in that, The drive assembly includes a gear system (18) evenly distributed along the circumferential surfaces of the first ring (2), the second ring (3), and the third ring (4). Gears (19) meshing with the gear system (18) are rotatably mounted on the measuring frame (1). The gears (19) are driven by a servo motor (20).

5. The automatic measurement device for half-value layers according to claim 1, characterized in that, The measuring frame (1) has a guide hole (22) at its upper end, and the guide hole (22) and the detector (8) have their central axes coincide.

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