A magnetic field strength measuring device

Abstract

This invention discloses a magnetic induction intensity measuring device, comprising a base plate, with support frames mounted at both the front and rear ends of the base, a rotating shaft mounted on the support frames and rotatably connected to the support frames, a coil fixedly mounted on the base plate to the right of the rotating shaft, the rotating shaft passing through the axis of the left side frame of the coil, and the coil being fixed to the rotating shaft by a fixing device, a pressure sensor and a pressure digital display screen fixedly mounted on the base plate; a pressure sensor is mounted on the base plate below the right side frame of the coil, and a pressure digital display screen is mounted on the right side above the base plate, the pressure sensor and the pressure digital display screen being connected via a data cable, and a magnet is mounted above the base. Using this magnetic induction intensity measuring device, the influence of the Ampere force generated in the opposite direction by the wire on one side of the coil on the Ampere force generated by the wire on the other side of the coil when calculating the magnetic induction intensity B can be eliminated, thus improving the accuracy of magnetic induction intensity measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic induction intensity measurement, in particular to a magnetic induction intensity measurement device. BACKGROUND

[0002] Magnetic induction intensity is the emphasis and difficulty of high school physics teaching. In combination with the experiments in the current physics textbook, teachers need to make teaching aids to show students the experiment. When measuring the magnetic induction intensity in the magnetic field, the wire is perpendicular to the direction of the magnetic field, and the formula B=F / (nIL) is used to calculate, wherein F is the ampere force, B is the magnetic induction intensity, I is the current intensity, L is the coil length, and n is the number of turns of the coil.

[0003] The patent CN2099358U sets a rotating shaft in the middle of the coil. When measuring the B value, the coil can be placed in the middle of the uniform magnetic field. The magnetic field is obtained by stacking two horseshoe magnets. Before electrifying, the coil plane is parallel to the magnetic induction line. After electrifying, the R resistance value is adjusted to make the current in the coil reach the required value. At this time, the coil will rotate an angle. Slowly add the weight in the hanging plate until the coil is pulled back to the original position. Record the current value I and the weight m of the hanging plate and weight. Then calculate the B value according to the formula B=F / (2nI·△L). However, the patent does not consider the influence of the upward ampere force generated by the right coil on the downward ampere force generated by the left coil on the measurement accuracy of the magnetic induction intensity B, which may lead to inaccurate measurement results of the magnetic induction intensity B.

[0004] The patent CN221528882U sets a measurement mechanism, a display mechanism, a magnetic field mechanism, and a moving mechanism. The coil for measuring the magnetic field is moved to the uniform magnetic field, and the current of the coil and the pressure sensor are recorded. Finally, the magnetic induction intensity is converted. In the patent, the coil on the upper side of the first coil 6 generates an upward ampere force, and the coil on the lower side of the first coil 6 generates a downward ampere force. When calculating the B value, the patent uses the pressure value measured by the pressure sensor to calculate the magnetic induction intensity B. The pressure value measured by the pressure sensor is the pressure value measured after subtracting the upward ampere force generated by the coil on the upper side of the first coil 6 from the downward ampere force generated by the coil on the lower side of the first coil 6. The patent directly uses the downward ampere force generated by the coil on the lower side of the first coil 6 as the pressure measured by the pressure sensor, ignoring the influence of the upward ampere force generated by the coil on the upper side of the first coil 6 on the measurement, which leads to inaccurate measurement results.

[0005] The existing magnetic induction intensity measurement devices do not consider the influence of the opposite direction ampere force generated by the coil on one side on the ampere force generated by the coil on the other side when calculating the magnetic induction intensity B, which leads to inaccurate measurement accuracy of the existing magnetic induction intensity measurement device.

[0006] Therefore, there is an urgent need to propose a method to eliminate the influence of the Ampere force generated by the wire on one side of the coil in the opposite direction on the Ampere force generated by the wire on the other side of the coil when calculating the magnetic induction intensity B, thereby improving the measurement accuracy of the magnetic induction intensity. Summary of the Invention

[0007] In view of the above problems, the purpose of the present invention is to provide a magnetic induction intensity measuring device. The present invention provides the following technical solutions: A magnetic induction line measuring device includes a bottom plate. Support frames are respectively installed at the front and rear ends of the base. A rotating shaft is installed on the support frames, and the rotating shaft is rotatably connected to the support frames. A coil is fixedly arranged on the bottom plate on the right side of the rotating shaft. The rotating shaft passes through the axis of the left side frame of the coil, and a fixing device is used to fix the coil on the rotating shaft 8. A pressure sensor and a pressure digital display screen are fixedly arranged on the bottom plate; a pressure sensor is arranged on the bottom plate below the right side frame of the coil, and a pressure digital display screen is arranged on the right side above the bottom plate. The pressure sensor is connected to the pressure digital display screen through a data cable. A magnet is arranged above the base. The magnet has a north pole and a south pole. The north pole and the south pole of the magnet are respectively arranged on the left and right sides of the coil.

[0008] Furthermore, it further includes a current measurement circuit. Wiring columns are arranged at both the front and rear ends of the bottom plate. In the current measurement circuit, there are a power supply, a switch K, an ammeter A, and a sliding rheostat R. The power supply, the switch, the coil, the ammeter A, and the sliding rheostat R form a current measurement circuit.

[0009] Furthermore, the shape of the coil can be rectangular or square.

[0010] Furthermore, the fixing device can be tape or a clamping device. The coil can be wound and fixed on the rotating shaft by tape, or the coil can be fixed on the rotating shaft by using a clamping device; Furthermore, the rotating shaft can be made of non-ferromagnetic material; Furthermore, the rotating shaft is an aluminum needle; Furthermore, the power supply can be an adjustable DC power supply or a DC battery pack.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This invention fixes one side of a coil to a rotating shaft, while the other side of the coil is mounted on a pressure sensor. Under the influence of a magnetic field, the coil fixed to the rotating shaft generates an upward Ampere force that directly acts on the rotating shaft. This upward Ampere force balances the downward tension exerted by the rotating shaft on the coil, thus canceling out the Ampere force generated by the wires in the coil on the rotating shaft. The coil mounted on the pressure sensor generates a downward Ampere force that directly acts on the pressure sensor, and the data is read using a digital pressure display. This invention eliminates the influence of the opposite Ampere force generated by the wires on one side of the coil on the Ampere force generated by the wires on the other side of the coil when calculating the magnetic induction intensity B, thereby improving the accuracy of magnetic induction intensity measurement.

[0012] The present invention has few components and a simple structure. Using the device of the present invention, the surface magnetic field strength of permanent magnets can be measured conveniently and quickly. The measured data is close to the actual working state of the permanent magnet. At the same time, the measurement is convenient, efficient and accurate. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of the present invention, including the current measuring circuit; Figure 2 This is a schematic diagram of the magnetic field line measuring device of the present invention; Figure 3 This is a front view of the structural schematic diagram of the magnetic field line measuring device of the present invention; Figure 4 This is a top view of the structural schematic diagram of the magnetic field line measuring device of the present invention.

[0014] In the diagram: 1. Terminal block; 2. Wire 1; 3. Pressure sensor; 4. Pressure digital display screen; 5. S pole; 6. Data cable; 7. Coil; 8. Rotating shaft; 9. Wire 2; 10. Base plate; 11. N pole; 12. Support frame. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] like Figures 1-4As shown, a magnetic field line measuring device includes a base plate 10. Support frames 12 are installed at the front and rear ends of the base plate 10, respectively. A rotating shaft 8 is mounted on the support frames 12 and rotatably connected to them. A coil 7 is fixedly installed on the base plate 10 to the right of the rotating shaft 8. The coil 7 can be rectangular or square. The rotating shaft 8 passes through the axis of the left side border of the coil 7, and a fixing device 3 is used to fix the coil 7 to the rotating shaft 8. The fixing device 3 can be tape or a clamping device. The coil 7 can be fixed to the rotating shaft 8 by wrapping it with tape or by using a clamping device. A pressure sensor 3 and a pressure digital display screen 4 are fixedly installed on the base plate 10. The rotating shaft 8 can be made of non-ferromagnetic material, such as aluminum needles used for knitting. A pressure sensor 3 is installed on the base plate 10 below the right side border of the coil 7, and a pressure digital display screen 4 is installed on the upper right side of the base plate 10. The pressure sensor 3 is connected to the pressure digital display screen 4 via a data cable 6. A magnet with an N pole 11 and a S pole 5 is placed above the base 10. The N pole 11 and S pole 5 of the magnet are respectively placed on the left and right sides of the coil 7. A current measuring circuit is also included, which provides current to the coil 7. Terminals 1 are provided at both the front and rear ends of the base plate 10. The current measuring circuit includes a power supply, a switch K, an ammeter A, and a sliding rheostat R. The power supply, switch, coil 7, ammeter A, and sliding rheostat R form the current measuring circuit. The positive terminal of the power supply is connected to one end of the switch K. One end of the ammeter A and the other end of the switch K are connected to the terminal 1 at the front and rear ends, respectively. The front terminal 1 is connected to one lead of the coil 7 via a second wire 9, and the rear terminal 1 is connected to the other lead of the coil 7 via a first wire 2. The other end of the ammeter A is connected to the negative terminal of the power supply via the sliding rheostat R, forming the current measuring circuit. The power supply can be an adjustable DC power supply or a DC battery pack.

[0017] In this embodiment, when the switch is closed, the power supply, switch, coil 7, ammeter A and sliding rheostat R form a current measuring circuit. At this time, the current flow direction of the wire in the right frame of coil 7 is from outside the paper to inside the paper, and the current flow direction of the wire in the left frame of coil 7 is from inside the paper to outside the paper. According to the left-hand rule, the wire in the right side frame of coil 7 will generate a downward Ampere force, and the wire in the left side frame of coil 7 will generate an upward Ampere force. Since the rotating shaft 8 passes through the axis of the left side frame of coil 7 and the coil 7 is fixed to the rotating shaft 8 by a fixing device, the upward Ampere force generated by the wire in the left side frame of coil 7 will directly act on the rotating shaft 8. Since the rotating shaft 8 is fixedly connected to the left side frame of coil 7 by the fixing device, the upward Ampere force generated by the wire in the left side frame of coil 7 will be canceled out by the rotating shaft 8 and will not affect the downward Ampere force generated by the wire in the right side frame of coil 7. The downward Ampere force generated by the wire in the right side frame of coil 7 will directly act on the pressure sensor 3. Since the pressure sensor 3 is connected to the pressure digital display screen 4, the number displayed on the pressure digital display screen 4 is the magnetic induction intensity generated by the downward Ampere force generated by the wire in the right side frame of coil 7 according to the formula B = F / (nIL). Furthermore, the current in the current measuring circuit can be changed by adjusting the sliding rheostat R, and multiple measurements can be performed to improve the accuracy of the measurement.

[0018] In the experimental apparatus of this invention, the length of the right coil L = 3.8 cm and the number of turns n = 116. When the switch of the current measuring circuit is closed, the current of coil 7 is changed by adjusting the sliding rheostat R. The power supply, switch, coil 7, ammeter A and sliding rheostat R form the current measuring circuit. Ten sets of experiments were conducted, and the specific results are shown in Table 1.

[0019] Table 1 Measured Results Number of experiments Current / mA Ampere force / mN Magnetic induction / T 1 36.413 3.322 0.020696723 2 56.14 5.292 0.021384832 3 80.55 7.448 0.020976476 4 104.79 9.604 0.020791735 5 127.33 11.76 0.020952459 6 149.84 13.72 0.020772308 7 169.7 15.582 0.020830504 8 202.05 18.326 0.020576298 9 231.3 20.874 0.020473329 10 265.53 23.716 0.020262184 It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0020] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A magnetic field line measuring device, comprising a base plate (10), support frames (12) respectively installed at the front and rear ends of the base, a rotating shaft (8) installed on the support frame (12), the rotating shaft (8) being rotatably connected to the support frame (12), a coil (7) fixedly installed on the base plate (10) on the right side of the rotating shaft (8), the rotating shaft (8) passing through the axis of the left side frame of the coil (7), and the coil (7) being fixed on the rotating shaft (8) by a fixing device, a pressure sensor (3) and a pressure digital display screen (4) fixedly installed on the base plate (10); a pressure sensor (3) is installed on the base plate (10) below the right side frame of the coil (7), a pressure digital display screen (4) is installed on the right side above the base plate (10), the pressure sensor (3) and the pressure digital display screen (4) are connected by a data cable (6), a magnet is installed above the base, the magnet has an N pole (11) and an S pole (5), and the N pole (11) and S pole (5) of the magnet are respectively installed on the left and right sides of the coil (7).

2. The magnetic field line measuring device according to claim 1, characterized in that, It also includes a current measuring circuit, with terminals (1) set at both the front and rear ends of the base plate. The current measuring circuit includes a power supply, a switch (K), an ammeter (A), and a sliding rheostat (R). The power supply, switch (K), coil (7), ammeter (A), and sliding rheostat (R) form the current measuring circuit.

3. The magnetic field line measuring device according to claim 2, characterized in that, The coil (7) is rectangular or square in shape.

4. A magnetic field line measuring device according to claim 3, characterized in that, The rotating shaft (8) is made of non-ferromagnetic material.

5. A magnetic field line measuring device according to claim 4, characterized in that, The rotating shaft (8) is an aluminum needle.

6. A magnetic field line measuring device according to claim 2, characterized in that, The power source is an adjustable DC power supply or a DC battery pack.

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