Cómo utilizar un medidor gaussiano para medir el campo magnético de un medidor
The working principle of a Gaussian meter mainly applies the Hall effect: when a current carrying conductor is placed in a magnetic field, a transverse potential difference will appear in the direction perpendicular to the magnetic field and current due to the Lorentz force. A Gaussian meter is an instrument for measuring magnetic fields based on the principle of the Hall effect. The Hall probe generates a Hall voltage in the magnetic field due to the Hall effect, and the measuring instrument converts the magnetic field strength value based on the Hall voltage and known Hall coefficient.
At present, Gaussian meters are generally equipped with unidirectional Hall probes, which can only measure the magnetic field strength in one direction, that is, they can only measure the magnetic field strength perpendicular to the direction of the Hall chip. In some high-end measurement fields, there are also Hall probes that can measure three-dimensional magnetic fields. Through the conversion of measuring instruments, the magnetic field strength in the X, Y, and Z directions can be displayed, and the maximum magnetic field strength can be obtained through trigonometric conversion. Gaussian meters are generally capable of measuring both DC and AC magnetic fields, with units that can be switched between displaying Gaussian units in Gs or international units in millitesla mT. Among them, measuring DC magnetic fields is the most commonly used in the industry. If real-time magnetic field measurement is required, the real function needs to be used, and the display screen will show real-time magnetic field values and polarities. When capturing peak magnetic fields and corresponding polarities during the measurement process, the hold function needs to be used. As shown in the figure below, the display screen will show dddhhhholddddhhh, and the displayed value and polarity are the peak magnetic field captured and its corresponding polarity. If there is no display, it is the real function. The MODE button can also be used to switch to the AC magnetic field testing mode, as shown in the screen below with the symbol dddhhh~dddhhh.
Precautions for using Gaussian meter:
When using a Gaussian meter to measure the magnetic field, the probe should not be excessively bent. The Hall chip at the end should generally be lightly pressed and in contact with the surface of the magnet. This is to ensure the fixing of the measurement point and to ensure that the probe is tightly attached to the measurement surface and is in a horizontal state, but not to press it hard. 2. The Hall chip can sense on both sides, but the values and polarities are different. The scale surface is used for convenient measurement and cannot be used as a measuring surface. The non scale surface is the measuring surface.
The Gaussian meter measures the magnetic field strength Bz perpendicular to the default measurement plane. The following figure is a simulation of a normal Z-axis magnetized magnet. It can be seen that the magnetic field is a vector, and the magnetic field strength on the Z-axis can be considered as Bz=. Due to the shortest magnetic circuit path at the corners, the magnetic field lines at the corners will be denser, and the magnetic field strength B will be stronger than the center. However, Bz may not necessarily be stronger than the center, but it is limited by the measurement area of the Hall chip. Generally, the measured magnetic field strength at the corners is stronger than that at the center, at least not lower than that at the center.
It should be noted that when the magnetization direction is different, even on the same measuring surface, the difference in measurement values is very large. For measuring dynamics or fitting magnetic fields at different measurement positions into waveform curves, a magnetic field scanner is required. It still needs to measure using unidirectional or three-dimensional Hall chips, and then output the magnetic field measurement curve by designing the measurement trajectory and data acquisition.