TW-HM-B Helmholtz coil magnetic field measurement instrument Introduction: Helmholtz coil magnetic field measuring instrument is one of the important experiments in the physical experiment syllabus of comprehensive universities and engineering colleges. This experiment can learn and master the measurement method of weak magnetic field, prove the principle of magnetic field superposition, and describe the magnetic field distribution according to the teaching requirements. In the traditional experiment of magnetic field measurement with Helmholtz coil, the magnetic induction intensity is generally measured with a probe coil and an AC voltmeter. Due to the large volume of the coil and the low grade of the pointer AC voltmeter, the measurement error is large. The instrument uses an advanced 95A integrated Hall sensor as the detector. The DC voltmeter is used to measure the output voltage of the sensor and detect the magnetic field generated by Helmholtz coil. The measurement accuracy is much better than that of the detection coil. The fixing parts of the instrument are firm and the experiment content is rich. This instrument can not only measure the magnetic field on the central axis of the single coil and Helmholtz coil, but also measure the magnetic field distribution in the radius plane. That is to say, it realizes the two-dimensional magnetic field measurement. Because the magnetic field in each direction of the coil radius direction is the same, it is also equivalent to the three-dimensional measurement. The instrument has been used by the Physical Experiment Teaching Center of Fudan University and has achieved good teaching results. Experiment items: 1. Measure the magnetic induction intensity of each point on the axis of a single current carrying circular coil, and compare the measured magnetic induction intensity with the theoretical calculated value; 2. Measure the magnetic induction intensity of each point on the radius plane of a single current carrying circular coil. 3. Measure the magnetic induction intensity on the central axis of Helmholtz coil and in the plane perpendicular to the central axis. 4. Under a fixed current, measure the magnetic induction intensity B (a) and B (b) generated by a single coil (coil a and coil b) on the axis respectively, and compare with the magnetic field B (a+b) generated by Helmholtz coil. 5. Measure the magnetic field distribution on the axis of Helmholtz coil when the spacing is d=R/2, d=R, d=3R/2 (R is the coil radius), and compare them to further prove the principle of magnetic field superposition. Technical indicators High sensitive millitesla meter: range 0-1.999 mT, resolution 0.001 mT DC constant current power supply: output current 0-200mA, stability 1% Test coil: turns 500, average radius 100mm Sensor measuring ruler: up and down movement range 0-160mm, up and down measurement resolution 0.02mm Coil center position: about 80mm (reading on vernier) Distance between sensor and marker line: 200mm Guide rail: length 500mm, ruler resolution 1mm Magnetic field measurement: error less than 3%
Introduction: Helmholtz coil magnetic field measuring instrument is one of the important experiments in the physical experiment syllabus of comprehensive universities and engineering colleges. This experiment can learn and master the measurement method of weak magnetic field, prove the principle of magnetic field superposition, and describe the magnetic field distribution according to the teaching requirements. In the traditional experiment of magnetic field measurement with Helmholtz coil, the magnetic induction intensity is generally measured with a probe coil and an AC voltmeter. Due to the large volume of the coil and the low grade of the pointer AC voltmeter, the measurement error is large. The instrument uses an advanced 95A integrated Hall sensor as the detector. The DC voltmeter is used to measure the output voltage of the sensor and detect the magnetic field generated by Helmholtz coil. The measurement accuracy is much better than that of the detection coil. The fixing parts of the instrument are firm and the experiment content is rich. This instrument can not only measure the magnetic field on the central axis of the single coil and Helmholtz coil, but also measure the magnetic field distribution in the radius plane. That is to say, it realizes the two-dimensional magnetic field measurement. Because the magnetic field in each direction of the coil radius direction is the same, it is also equivalent to the three-dimensional measurement. The instrument has been used by the Physical Experiment Teaching Center of Fudan University and has achieved good teaching results.
