A test device for measuring the diameter of an object by light scattering method and a test method thereof

Abstract

This invention discloses a testing device and method for measuring the diameter of an object using the light scattering method. The device further includes a movable frame mounted on a support, a laser mechanism slidably mounted on the movable frame, a drive mechanism mounted on the movable frame for moving the laser mechanism, a stepper motor mounted on a base frame, a rotating arm mounted on the base frame and connected to the stepper motor, and a light intensity sensor mounted on the rotating arm. This invention employs a drive mechanism to control the movement of the laser beam adjustment frame via a stepper motor, ensuring consistent movement distances each time. After the semiconductor laser position changes, the point of strongest reflected light intensity changes. The light intensity sensor automatically captures this point, thus obtaining accurate incident and reflection angles. The diameter of the cylindrical sample under test is then automatically calculated using an algorithm, ensuring experimental accuracy and simplifying operation for operators, reducing operational complexity.

Description

Technical Field

[0001] This invention relates to an experiment for testing the diameter of an object using the light scattering method, specifically a testing device and method for measuring the diameter of an object using the light scattering method. Background Technology

[0002] Existing experimental setups for measuring object diameter using the light scattering method consist of a laser, a movable frame for mounting the laser, a disk, and a calibration lens moving platform. During the experiment, the laser's movement is manually adjusted each time, and the point of strongest light intensity reflected after the laser shines on the object is visually located to determine the incident and reflection angles, which are then used for calculations. However, manually adjusting the laser's movement results in inconsistent movement distances, inevitably leading to some deviation. Furthermore, visually locating the point of strongest light intensity also introduces some error, causing corresponding deviations in the obtained incident and reflection angles. This results in inaccurate calculations, affecting the experimental results. Moreover, the manual operation required for each adjustment is cumbersome and yields inaccurate data. Therefore, this paper proposes a testing device and method for measuring object diameter using the light scattering method. Summary of the Invention

[0003] The purpose of this invention is to solve the above problems by providing a testing device and method for measuring the diameter of an object using the light scattering method.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a testing device for measuring the diameter of an object using the light scattering method, comprising a base frame and a support mounted on the base frame; characterized in that it further comprises a movable frame mounted on the support, a laser mechanism slidably mounted on the movable frame, a drive mechanism mounted on the movable frame for driving the laser mechanism to move, a stepper motor mounted on the base frame, a rotating arm mounted on the base frame and connected to the stepper motor, and a light intensity sensor mounted on the rotating arm; a disk is also mounted on the base frame, and the disk is provided with an angle indicator.

[0005] More preferably, the stepper motor is connected to an angle encoder.

[0006] More preferably, the laser mechanism includes a laser beam adjustment frame slidably mounted on a movable frame and a semiconductor laser mounted on the laser beam adjustment frame; the drive mechanism includes a stepper motor mounted on the movable frame, a lead screw connected to the stepper motor, and a nut seat movably mounted on the lead screw and connected to the laser beam adjustment frame.

[0007] More preferably, the movable frame is also provided with a slide rail, and the laser beam adjustment frame is provided with a slide groove adapted to the slide rail.

[0008] A test method for a light scattering method for measuring the diameter of an object, characterized in that the test method is as follows:

[0009] 1) Instrument preparation: Turn on the semiconductor laser power supply and adjust the semiconductor laser power intensity;

[0010] 2) Beam adjustment: Place a cylindrical sample at the center of the disk so that the laser beam hits the surface of the cylindrical sample. By adjusting the focusing lens at the front of the semiconductor laser, the size of the beam hitting the surface of the cylindrical sample at the current distance is minimized.

[0011] 3) Optical path adjustment: Remove the cylindrical sample from the center of the disk, then place the calibration lens at the zero mark of the disk's center. Adjust the laser beam adjustment frame and the position of the semiconductor laser using stepper motor 2 so that the laser beam is incident on the calibration lens. After reflection by the calibration lens, the laser beam returns to the center of the semiconductor laser's output aperture. At this point, the laser beam passes through the center of the disk. Then remove the calibration lens, and place the sample back at the center of the disk. Observe the reflected light returning to the center of the semiconductor laser's output aperture; the semiconductor laser's position is now its initial position.

[0012] 4) Conduct the experiment: Change the position of the laser beam adjustment frame and the semiconductor laser by stepper motor 2, so that the semiconductor laser moves in one direction. Set the position of the semiconductor laser as b, and the movement interval is Δb. After the movement interval is adjusted, control the rotating arm to rotate by the stepper motor with angle encoder. When the light intensity sensor on the rotating arm receives the maximum light intensity signal (i.e., the position of the scattering spot), stop the rotation. The angle position 2α and the position of the semiconductor laser b are automatically recorded by the angle encoder on the stepper motor. Then, change the position b by Δb again and use the same method to measure the scattering spot angle position 2α after each change of position b, until 2α is 90°.

[0013] 5) Calculation: Let R be the sample radius, b be the position of the semiconductor laser, and let the beam reflect after hitting the target. Let the reflection angle be α. Then, the reflection angle reflected from the side of the sample is equal to the incident angle α, derived from geometry. Define the total reflection angle ,get By aiming at the change in distance b, Δb, and the scattering angle Change △ Calculation of differential scattering cross section from experimental data ,pass Initially calculate R0, measure the distance r from the scattering center, and then... Then by doing The slopes K1 and R1 are obtained by linear fitting.

[0014] 6) Then, repeat the data processing procedure in step 5) iteratively multiple times until R... n+1 With R n If they are basically the same, they can be used as the value of R, thus determining the radius of the cylinder.

[0015] This invention employs a drive mechanism that uses a stepper motor to control the movement of the laser beam adjustment frame, ensuring consistent movement distances each time. Simultaneously, by incorporating a stepper motor, angle encoder, and light intensity sensor, the point of strongest reflected light intensity changes after the semiconductor laser's position shifts. The light intensity sensor automatically captures this point, thus determining the accurate incident and reflection angles. An algorithm then automatically calculates the diameter of the cylindrical sample under test, ensuring experimental accuracy, simplifying operation, and reducing operational complexity. Attached Figure Description

[0016] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Appendix Figure 2 This is a schematic diagram of the structure of the present invention;

[0018] Appendix Figure 3 This is a partial cross-sectional schematic diagram of the drive mechanism in this invention;

[0019] Appendix Figure 4 The scattering angle in this invention A graph showing the relationship between the target distance b and the target distance b.

[0020] Appendix Figure 5 In this invention, the differential scattering cross section and x (x represents) Relationship data diagram;

[0021] Appendix Figure 6 This invention is based on The sample radius data table is obtained from the relationship with x.

[0022] Legend: 1. Base frame; 11. Disc; 12. Angle indicator; 2. Support; 3. Moving frame; 31. Slide rail; 4. Laser mechanism; 41. Laser beam adjustment frame; 42. Semiconductor laser; 43. Slide groove; 5. Drive mechanism; 51. Stepper motor II; 52. Lead screw; 53. Nut seat; 6. Stepper motor; 7. Rotating arm; 8. Light intensity sensor. Detailed Implementation

[0023] The following description, in conjunction with the accompanying drawings, further illustrates the testing apparatus and method for measuring the diameter of an object using the light scattering method described in this invention.

[0024] See Figure 1-6As shown, a test device for measuring the diameter of an object using the light scattering method includes a base frame 1 and a support 2 mounted on the base frame 1; it is characterized by further including a movable frame 3 mounted on the support 2, a laser mechanism 4 slidably mounted on the movable frame 3, a drive mechanism 5 mounted on the movable frame 3 for driving the laser mechanism 4 to move, a stepper motor 6 mounted on the base frame 1, a rotating arm 7 mounted on the base frame 1 and connected to the stepper motor 6, and a light intensity sensor 8 mounted on the rotating arm 7; a disk 11 is also mounted on the base frame 1, and the disk 11 is provided with an angle indicator 12; the stepper motor 6 is connected to an angle encoder;

[0025] By employing the drive mechanism 5, the laser beam adjustment frame 41 is moved by the stepper motor 51, and the movement distance is kept consistent each time. Simultaneously, by using the stepper motor 6, angle encoder, and light intensity sensor 8, the point of strongest reflected light intensity changes after the position of the semiconductor laser 42 moves. The light intensity sensor 8 automatically captures the point of strongest light intensity, thereby obtaining accurate incident angle and reflection angle. This ensures the accuracy of the experiment, facilitates the operation of the operator, and reduces the complexity of operation.

[0026] When the light intensity sensor 8 captures the point of strongest light intensity, the stepper motor 6 drives the rotating arm 7 to rotate, and the rotating arm 7 drives the light intensity sensor 8 to rotate to capture the point of strongest light. After the capture is completed, the rotation angle is obtained through the angle encoder.

[0027] Furthermore, the laser mechanism 4 includes a laser beam adjustment frame 41 slidably mounted on the movable frame 3 and a semiconductor laser 42 mounted on the laser beam adjustment frame 41; the drive mechanism 5 includes a second stepper motor 51 mounted on the movable frame 3, a lead screw 52 connected to the second stepper motor 51, and a nut seat 53 movably mounted on the lead screw 52 and connected to the laser beam adjustment frame 41.

[0028] When the semiconductor laser 42 moves, the stepper motor 51 drives the lead screw 52 to rotate. The lead screw 52 drives the laser beam adjustment frame 41 to move linearly through the screw engagement with the nut seat 53, thereby driving the semiconductor laser 42 to move linearly.

[0029] Furthermore, the movable frame 3 is also provided with a slide rail 31, and the laser beam adjustment frame 41 is provided with a slide groove 43 adapted to the slide rail 31; the slide rail 31 and the slide groove 43 are provided to limit and guide the movement of the laser beam adjustment frame 41.

[0030] The test method of this invention:

[0031] 1) First, prepare the instrument, turn on the power supply of semiconductor laser 42 and adjust the power intensity of semiconductor laser 42;

[0032] 2) Beam adjustment: Place a cylindrical sample at the center of the disk so that the laser beam hits the surface of the cylindrical sample. Adjust the focusing lens at the front of the semiconductor laser 42 to minimize the size of the beam that hits the surface of the cylindrical sample at the current distance.

[0033] 3) Optical path adjustment: Remove the cylindrical sample from the center of disk 11, then place the calibration lens at the zero mark of the center of the disk. Then, adjust the position of the laser beam adjustment frame 41 and the semiconductor laser 42 by stepper motor 51 so that the laser beam is incident on the calibration lens. After being reflected by the calibration lens, the laser beam can return to the center of the output aperture of the semiconductor laser 42. At this time, the laser beam passes through the center. Then remove the calibration lens, and then place the sample at the center of disk 11 to observe the reflected light returning to the position of semiconductor laser 42. At this time, the center of the output aperture of semiconductor laser 42 is the initial position.

[0034] 4) Conduct the experiment: Move the laser beam adjustment frame and semiconductor laser 42 in one direction using stepper motor 51. Set the position of semiconductor laser 42 to b, and the interval between each movement to Δb, for example, set the interval between each movement to 0.1cm. After the movement interval is adjusted, rotate the rotating arm 7 using stepper motor 6. Stop rotating when the light intensity sensor 8 on the rotating arm 7 receives the maximum light intensity signal (i.e., the position of the scattering spot). Automatically record the angle position 2α and the position b of semiconductor laser 42 using the angle encoder on stepper motor 6. Then, change the position b again by Δb and measure the angle position 2α of the scattering spot after each change of position b using the same method until 2α is 90°.

[0035] 5) Calculation: Set R as the sample radius, and calculate the change in aiming distance b Δb and scattering angle. Change △ Calculation of differential scattering cross section from experimental data ,pass Initially calculate R0, measure the distance r from the scattering center (i.e., the distance from the light intensity sensor receiving surface to the center of disk 11), and then calculate... Then by doing The slopes K1 and R1 are obtained by linear fitting.

[0036] 6) Then, repeat the data processing procedure in step 5) iteratively multiple times until R... n+1 With R n If they are basically the same, they can be used as the value of R, thus determining the radius of the cylinder. Once the radius is determined, the diameter of the sample can be known.

[0037] Experimental data recording and processing:

[0038] pass Scattering angle The relationship between the data and the aiming distance b is shown in the graph, as follows: Figure 4 As shown in the figure, by setting the intercept of the trend line to 0 and obtaining the slope K, a preliminary estimate of the cylinder radius R0 can be obtained;

[0039] Construct the differential scattering cross section (Unit: cm / radian) and Relational data, including the above... As x; such as Figure 5 As shown,

[0040] pass The slope K1 in the graph of the relationship with x represents R1 = 2K1, as shown below. Figure 6 As shown,

[0041] Replace R0 with R1 and repeat the above data processing process iteratively to obtain K2 and R2; similarly, use R... n Replace R0 and repeat the above process to obtain R. n+1 Until R n+ 1 With R n The sizes are basically the same, which determines the radius of the sample cylinder.

[0042] The scope of protection of this invention is not limited to the above embodiments and their variations. Conventional modifications and substitutions made by those skilled in the art based on the content of these embodiments are all within the scope of protection of this invention.

Claims

1. A test method for a test device for measuring the diameter of an object using the light scattering method, characterized in that: The testing method is as follows: 1) Instrument preparation: Turn on the semiconductor laser power supply and adjust the semiconductor laser power intensity; 2) Beam adjustment: Place a cylindrical sample at the center of the disk so that the laser beam hits the surface of the cylindrical sample. By adjusting the focusing lens at the front of the semiconductor laser, the size of the beam hitting the surface of the cylindrical sample at the current distance is minimized. 3) Optical path adjustment: Remove the cylindrical sample from the center of the disk, then place the calibration lens at the zero mark of the disk's center. Adjust the laser beam adjustment frame and the position of the semiconductor laser using stepper motor 2 so that the laser beam is incident on the calibration lens. After reflection by the calibration lens, the laser beam returns to the center of the semiconductor laser's output aperture. At this point, the laser beam passes through the center of the disk. Then remove the calibration lens, and place the sample back at the center of the disk. Observe the reflected light returning to the center of the semiconductor laser's output aperture; the semiconductor laser's position is now its initial position. 4) Conduct the experiment: Change the position of the laser beam adjustment frame and the semiconductor laser by stepper motor 2, so that the semiconductor laser moves in one direction. Set the position of the semiconductor laser to b, and the movement interval is Δb. After the movement interval is adjusted, control the rotating arm to rotate by stepper motor with angle encoder. When the light intensity sensor on the rotating arm receives the maximum light intensity signal, stop the rotation. The angle position 2α and the semiconductor laser position b are automatically recorded by the angle encoder on the stepper motor. Then, after changing position b by △b again, the same method is used to measure the scattering spot angle position 2α after each change of position b, until 2α is 90°. 5) Calculation: Let R be the sample radius, b be the position of the semiconductor laser, and let the beam reflect after hitting the target. Let the reflection angle be α. Then the reflection angle reflected from the side of the sample is equal to the incident angle α, derived from geometry. Define the total reflection angle ,get By aiming at the change in distance b, Δb, and the scattering angle Change △ Calculation of differential scattering cross section from experimental data ,pass Initially calculate R0, measure the distance r from the scattering center, and then... Then by doing The slopes K1 and R1 are obtained by linear fitting. 6) Then, repeat the data processing procedure in step 5) iteratively multiple times until R... n+1 With R n If they are basically the same, they can be used as the value of R, thus determining the radius of the cylinder.

2. The testing method of the testing device for measuring the diameter of an object by light scattering method according to claim 1, characterized in that: The testing device includes a base frame (1) and a bracket (2) mounted on the base frame (1); it also includes a movable frame (3) mounted on the bracket (2), a laser mechanism (4) slidably mounted on the movable frame (3), a drive mechanism (5) mounted on the movable frame (3) for driving the laser mechanism (4) to move, a stepper motor (6) mounted on the base frame (1), a rotating arm (7) mounted on the base frame (1) and connected to the stepper motor (6), and a light intensity sensor (8) mounted on the rotating arm (7); a disk (11) is also mounted on the base frame (1), and an angle indicator (12) is provided on the disk (11).

3. The test method of the test device for measuring the diameter of an object by light scattering method according to claim 2, characterized in that: The stepper motor (6) is connected to an angle encoder.

4. The test method of the test device for measuring the diameter of an object by light scattering method according to claim 2, characterized in that: The laser mechanism (4) includes a laser beam adjustment frame (41) slidably mounted on the movable frame (3) and a semiconductor laser (42) mounted on the laser beam adjustment frame (41); the drive mechanism (5) includes a second stepper motor (51) mounted on the movable frame (3), a lead screw (52) connected to the second stepper motor (51), and a nut seat (53) movably mounted on the lead screw (52) and connected to the laser beam adjustment frame (41).

5. The test method of the test device for measuring the diameter of an object by light scattering method according to claim 4, characterized in that: The movable frame (3) is also provided with a slide rail (31), and the laser beam adjustment frame (41) is provided with a slide groove (43) that is adapted to the slide rail (31).

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