Gravitational acceleration measuring device

Abstract

A gravitational acceleration measuring device comprises a simple pendulum leveling support with a base and a reflecting plate, a through hole is formed in the middle of the reflecting plate, the upper end of the simple pendulum leveling support is connected with a cycloid, and the lower end, penetrating through the through hole, of the cycloid is fixedly provided with a freely-drooping pendulum bob; the upper surface of the base is provided with a gravitational acceleration testing device which is matched with the pendulum bob to measure gravitational acceleration; the gravitational acceleration testing device comprises a device main body, a microcontroller, a liquid crystal display screen, a laser range finder, an infrared obstacle avoidance instrument, a button switch and a USB (Universal Serial Bus) interface; the device further comprises a horizontal adjusting device, the horizontal adjusting device comprises a gradienter and automatic lifting rods, the automatic lifting rods are arranged at the four end feet of the base, and the gradienter is installed on the base. According to the gravitational acceleration measuring device, the microcontroller is utilized, various sensors are matched, automatic data measuring and processing processes are achieved, experimental operation is simplified, and experimental errors are reduced.

Description

Technical Field

[0001] The utility model specifically relates to a device for measuring gravitational acceleration. Background Technique

[0002] The experiment of measuring gravitational acceleration is a common physics experiment in junior and senior high schools. Through experimental operations, the local gravitational acceleration can be accurately measured. Due to the lack of experimental funds in junior and senior high school laboratories, it is impossible to equip high-precision and highly automated experimental instruments for measuring gravitational acceleration for students to conduct experimental operations. Generally, a simple pendulum with low cost is used to measure gravitational acceleration, and a scale and vernier caliper are used to measure the pendulum length, and the method of manual counting and manual timing with a stopwatch is used to measure relevant data, and the processing of experimental data is also completed manually. This method not only takes time and effort, but also has relatively large errors. Content of the Utility Model

[0003] In view of the above, the utility model provides a device for measuring gravitational acceleration to solve the problems raised in the above background technique.

[0004] The technical solution adopted by the utility model to solve its technical problems is: a device for measuring gravitational acceleration is provided, which includes a single pendulum leveling bracket with a base. An adjustable-height reflector is movably installed on the single pendulum leveling bracket. A through hole is opened in the middle of the reflector, and a height adjustment knob is provided at the installation position of the reflector and the single pendulum leveling bracket. The upper end of the single pendulum leveling bracket is connected with a pendulum line, and a freely falling pendulum bob is fixed at the lower end of the pendulum line passing through the through hole; a gravitational acceleration test device for cooperating with the pendulum bob to measure gravitational acceleration is arranged on the upper surface of the base. The gravitational acceleration test device includes a device main body, a microcontroller, a liquid crystal display screen, a laser rangefinder, an infrared obstacle avoidance instrument, a button switch, and a USB interface. The microcontroller, the liquid crystal display screen, the laser rangefinder, the infrared obstacle avoidance instrument, the button switch, and the USB interface are respectively arranged on the device main body. The device main body is located on one side of the pendulum bob, and the center of the sensor probe of the infrared obstacle avoidance instrument and the center of the pendulum bob are at the same height; a horizontal adjustment device for adjusting the levelness of the base is further included. The horizontal adjustment device includes a level for measuring the levelness of the base and a plurality of independently adjustable automatic lifting rods. The plurality of automatic lifting rods are arranged at the four end feet of the base, and the level is installed on the base. The output end of the level is connected to the input end of the microcontroller, and the output end of the microcontroller is respectively connected to the input ends of the automatic lifting rods. The lifting of the automatic lifting rods is adjusted respectively to keep the base horizontal for gravitational acceleration testing.

[0005] Further, a soft plug for cooperating with the through hole is further included, and the soft plug is inserted into the through hole of the reflector to fix the pendulum line.

[0006] Further, the device main body is located on one side of the pendulum bob, and the distance is 1 cm - 10 cm.

[0007] Furthermore, the distance between the reflector and the pendulum bob is 60 cm - 110 cm.

[0008] The device for measuring the acceleration due to gravity of the present utility model utilizes a microcontroller and cooperates with a variety of sensors to realize an automated data measurement and processing process, simplifies the experimental operation, reduces experimental errors, and lowers the experimental cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a three-dimensional structural schematic diagram of the present utility model.

[0010] Figure 2 is a three-dimensional structural schematic diagram of the acceleration due to gravity test device.

[0011] Figure 3 is a circuit schematic diagram of the present utility model.

[0012] In the figure, 1, base; 2, single pendulum leveling bracket; 3, reflector; 4, height adjustment knob; 5, through hole; 6, soft plug; 7, pendulum line; 8, pendulum bob; 9, device main body; 10, level; 11, automatic lifting rod; 12, infrared obstacle avoidance instrument; 13, laser rangefinder; 14, microcontroller; 15, liquid crystal display screen; 16, push-button switch; 17, USB interface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] The following further describes the present utility model in conjunction with the accompanying drawings and some embodiments.

[0014] In Figures 1-3 , a device for measuring the acceleration due to gravity includes a single pendulum leveling bracket 2 with a base 1. An adjustable-height reflector 3 is movably installed on the single pendulum leveling bracket 2. A through hole 5 is formed in the middle of the reflector 3, and a height adjustment knob 4 is provided at the installation position of the reflector 3 and the single pendulum leveling bracket 2. The upper end of the single pendulum leveling bracket 2 is connected with a pendulum line 7. The pendulum line 7 passes through the lower end of the through hole 5 and is fixed with a freely hanging pendulum bob 8 at the lower end. First step, before the experiment, first adjust the experimental instrument. The base 1 is kept horizontally stable. Place the acceleration due to gravity test device on the base 1. Fix one end of the pendulum line 7 on the pendulum bob 8, and the other end passes through the through hole 5 of the reflector 3 and is fixed at the middle position of the single pendulum leveling bracket 2. Adjust the height of the pendulum bob 8. At the same time, adjust the height adjustment knob 4 to fix the reflector 3 at a certain height. Plug the soft plug 6 into the through hole 5 of the reflector 3 to fix the pendulum line 7, so that the center of the pendulum bob 8 and the center of the sensor probe of the infrared obstacle avoidance instrument 12 are at the same height. Adjust the acceleration due to gravity test device so that the probe of the infrared obstacle avoidance instrument 12 of the acceleration due to gravity test device is directly facing the stationary pendulum bob 8. The acceleration due to gravity test device is located on one side of the pendulum bob 8. Except for the pendulum bob 8, ensure that there is no obstruction within 30 cm in front of the probe of the infrared obstacle avoidance instrument 12, which does not affect the swing of the pendulum bob 8.

[0015] In this embodiment, a gravitational acceleration testing device for cooperating with the pendulum bob 8 to measure the gravitational acceleration is provided on the upper surface of the base 1. The gravitational acceleration testing device includes a device main body 9, a microcontroller 14, a liquid crystal display screen 15, a laser rangefinder 13, an infrared obstacle avoidance device 12, a push button switch 16, and a USB interface 17. The microcontroller 14, the liquid crystal display screen 15, the laser rangefinder 13, the infrared obstacle avoidance device 12, the push button switch 16, and the USB interface 17 are respectively arranged on the device main body 9. The device main body 9 is located on one side of the pendulum bob 8, and the center of the sensor probe of the infrared obstacle avoidance device 12 and the center of the pendulum bob 8 are at the same height. In the second step, after the experimental preparation work is completed, a 5V DC voltage can be provided to the USB interface 17 of the gravitational acceleration testing device through a USB data cable. The gravitational acceleration testing device immediately starts to work, displays "Measuring", and the laser rangefinder 13 starts to measure the pendulum length. After measuring the pendulum length 100 times and taking the average value, it is displayed on the first line of the liquid crystal display screen 15. The second line of the liquid crystal display screen 15 displays "Press the button". Then, pull the pendulum bob 8, with the swing angle less than 5°, and let the pendulum bob 8 start to swing and perform simple harmonic motion. When the pendulum ball swings to the highest point, press the push button switch 16 on the device main body 9. The liquid crystal display screen 15 displays "go!", and the gravitational acceleration testing device starts to automatically measure and displays "period", "number of periods", and "gravitational acceleration value" in real time. When the number of periods is displayed as N = 30 or N = 50, press the push button switch 16 to stop the measurement, and the final "period", "number of periods", and "gravitational acceleration value" are displayed on the liquid crystal display screen 15. In the third step, pull out the soft plug 6 of the reflector 3, adjust the height adjustment knob 4, fix it after changing the height of the reflector 3, then plug the soft plug 6 into the through hole 5 of the reflector 3, press the push button switch 16 on the device main body 9, and repeat step 2 to measure the data under different pendulum lengths. In the fourth step, after the measurement is completed, the gravitational acceleration testing device is turned off, all data is cleared, and the power connection is disconnected.

[0016] In this embodiment, a horizontal adjustment device for adjusting the levelness of the base 1 is further included. The horizontal adjustment device includes a level 10 for measuring the levelness of the base 1 and a plurality of independently adjustable automatic lifting rods 11. The plurality of automatic lifting rods 11 are arranged at the four end feet of the base 1. The level 10 is installed on the base 1. The output end of the level 10 is connected to the input end of the microcontroller 14, and the output end of the microcontroller 14 is respectively connected to the input ends of the automatic lifting rods 11. The lifting of the automatic lifting rods 11 is adjusted respectively to keep the base 1 level for gravitational acceleration testing. During the experiment, the level 10 measures the levelness of the base 1 at all times and performs lifting actions by independently adjusting the automatic lifting rods 11 at the four end feet of the base 1 to ensure that the base 1 remains level and stable and does not affect the normal progress of the experiment.

[0017] In this embodiment, it further includes a soft plug 6 used in cooperation with the through hole 5. The soft plug 6 is inserted into the through hole 5 of the reflector 3 to fix the cycloid 7. By adjusting the height of the reflector 3 and fixing the cycloid 7 with the soft plug 6 to change the pendulum length of the simple pendulum, it is not necessary to reinstall the simple pendulum, making the adjustment of the pendulum length more convenient and rapid.

[0018] In this embodiment, the device main body 9 is located on one side of the pendulum bob 8, and the distance is 1 cm - 10 cm. The gravitational acceleration testing device is located on one side of the pendulum bob 8. Except for the pendulum bob 8, it is ensured that there is no obstruction within 30 cm in front of the probe of the infrared obstacle avoidance sensor 12, so as not to affect the swing of the pendulum bob 8.

[0019] In this embodiment, the distance between the reflector 3 and the pendulum bob 8 is 60 cm - 110 cm, which is convenient for changing the pendulum length of the simple pendulum, making the adjustment of the pendulum length more convenient and rapid.

[0020] In this embodiment, the microcontroller 14 is a common electrical component, such as a single-chip microcomputer of the model AT89C2051 or TMS320VC5509A, etc., which has a built-in clock and automatically measures the total time (Δt) of the simple pendulum swing.

[0021] In this embodiment, the infrared obstacle avoidance sensor 12 is a common infrared obstacle avoidance sensor 12 device, such as an infrared obstacle avoidance sensor 12 device of the model LM393, E18-D80NK, etc. By using the infrared obstacle avoidance sensor 12, it senses the pendulum bob 8 of the simple pendulum, automatically records the number of swings (n) of the simple pendulum, and calculates the average period (T = Δt / n) in real time.

[0022] In this embodiment, the laser rangefinder 13 is a common laser rangefinder 13 device, such as a laser rangefinder 13 of the models SW-T100 / T60 / T40, LDM-T100, etc. The laser rangefinder 13 is used to automatically measure the pendulum length (L) of the simple pendulum.

[0023] In this embodiment, the device for measuring gravitational acceleration processes the experimental data in real time according to the variant formula [g = L(2π / T)²] of the simple pendulum period formula, so as to obtain the local gravitational acceleration.

[0024] In this embodiment, the spirit level 10 is a common horizontal sensor, such as a horizontal sensor of the models PLS30, PLS40, etc.

[0025] In this embodiment, the automatic lifting rod 11 is a common electric lifting rod, such as an electric lifting rod of the models DPB-TBZ219Y, YOFS-A1, etc.

[0026] When the present utility model is specifically implemented: First step, before the experiment, first adjust the experimental instrument. The base 1 is kept horizontal and stable. Place the gravitational acceleration testing device on the base 1. Adjust the height adjustment knob 4 to fix the reflector 3 at a certain height. Plug the soft plug 6 into the through hole 5 of the reflector 3, fix the pendulum line 7, and make the center of the pendulum bob 8 and the center of the sensor probe of the infrared obstacle avoidance instrument 12 at the same height. Adjust the gravitational acceleration testing device so that the probe of the infrared obstacle avoidance instrument 12 of the gravitational acceleration testing device is directly facing the stationary pendulum bob 8. The gravitational acceleration testing device is located on one side of the pendulum bob 8. Second step, after the experimental preparation work is done, a 5V DC voltage can be provided to the USB interface 17 of the gravitational acceleration testing device through a USB data cable. The gravitational acceleration testing device immediately starts to work and displays "Measuring". The laser rangefinder 13 starts to measure the pendulum length. After measuring the pendulum length 100 times and taking the average value, it is displayed on the first line of the liquid crystal display screen 15. The second line of the liquid crystal display screen 15 displays "Press the button". Then, pull the pendulum bob 8, with the swing angle less than 5°, and let the pendulum bob 8 start to swing and perform simple harmonic motion. When the pendulum ball swings to the highest point, press the button switch 16 on the device main body 9. The liquid crystal display screen 15 displays "go!" and the gravitational acceleration testing device starts to automatically measure and real-time display "period", "number of periods", and "gravitational acceleration value". When the number of periods is displayed as N = 30 or N = 50, press the button switch 16 to stop the measurement. The final "period", "number of periods", and "gravitational acceleration value" are displayed on the liquid crystal display screen 15. Third step, pull out the soft plug 6 of the reflector 3, adjust the height adjustment knob 4, change the height of the reflector 3 and then fix it. Then plug the soft plug 6 into the through hole 5 of the reflector 3, press the button switch 16 on the device main body 9, and repeat step 2 to measure the data under different pendulum lengths. Fourth step, after the measurement is completed, the gravitational acceleration testing device is turned off, all data is cleared, and the power connection is disconnected.

[0027] It should be noted that: In the description of the present utility model, the meaning of "a plurality of" is two or more, unless otherwise specifically defined. In the present utility model, unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; the circuits described in the present utility model are all common circuits in the art, and other related components are all commonly used existing components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0028] For those skilled in the art, it is obvious that the utility model patent is not limited to the details of the above exemplary embodiments, and the utility model patent can be implemented in other specific forms without departing from the spirit or basic characteristics of the utility model patent. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the utility model patent is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the utility model patent. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A device for measuring the acceleration due to gravity, characterized in that: It includes a single-pendulum leveling bracket with a base. An adjustable-height reflector is movably installed on the single-pendulum leveling bracket. A through hole is formed in the middle of the reflector, and a height adjustment knob is provided at the installation position of the reflector and the single-pendulum leveling bracket. A pendulum string is connected to the upper end of the single-pendulum leveling bracket, and a freely hanging pendulum bob is fixed at the lower end of the pendulum string passing through the through hole. A gravitational acceleration testing device for cooperating with the pendulum bob to measure the gravitational acceleration is provided on the upper surface of the base. The gravitational acceleration testing device includes a device main body, a microcontroller, a liquid crystal display screen, a laser rangefinder, an infrared obstacle avoidance instrument, a button switch, and a USB interface. The microcontroller, the liquid crystal display screen, the laser rangefinder, the infrared obstacle avoidance instrument, the button switch, and the USB interface are respectively arranged on the device main body. The device main body is located on one side of the pendulum bob, and the center of the sensor probe of the infrared obstacle avoidance instrument and the center of the pendulum bob are at the same height. It also includes a horizontal adjustment device for adjusting the levelness of the base. The horizontal adjustment device includes a spirit level for measuring the levelness of the base and several independently adjustable automatic lifting rods. The several automatic lifting rods are arranged at the four end feet of the base. The spirit level is installed on the base, the output end of the spirit level is connected to the input end of the microcontroller, and the output end of the microcontroller is respectively connected to the input ends of the automatic lifting rods. The lifting of the automatic lifting rods is adjusted respectively to keep the base level for gravitational acceleration testing.

2. The device for measuring the acceleration of gravity according to claim 1, wherein: It also includes a soft plug for cooperating with the through hole. The soft plug is inserted into the through hole of the reflector to fix the pendulum string.

3. The gravity acceleration measuring device according to claim 1, characterized in that: The device main body is located on one side of the pendulum bob, and the distance is 1 cm - 10 cm.

4. The device for measuring the acceleration of gravity according to claim 1, wherein: The distance between the reflector and the pendulum bob is 60 cm - 110 cm.

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