How to use a Gauss meter to measure the surface gauss value

Gauss meter, also known as Tesla meter, is usually used as a measuring tool for surface magnetism. The following figure shows the widely used Japanese KANETEC Gauss meter.

The working principle of a Gauss meter mainly applies the Hall effect: when a current carrying conductor is placed in a magnetic field, due to the Lorentz force, there will be a lateral potential difference in the direction perpendicular to the magnetic field and current. Gauss meters are instruments that measure magnetic fields based on the principle of the Hall effect. The Hall probe generates Hall voltage in the magnetic field due to the Hall effect, The measuring instrument converts the magnetic field intensity value based on Hall voltage and known Hall coefficient.

At present, Gaussian meters are generally equipped with unidirectional Hall probes, which can only measure the magnetic field intensity in one direction, that is, can only measure the magnetic field intensity perpendicular to the direction of the Hall chip. In some high-end measurement fields, there are Hall probes that can measure three-dimensional magnetic fields. Through the conversion of measuring instruments, the magnetic field intensity in X, Y and Z directions can be displayed at the same time. The maximum magnetic field intensity can be obtained through Trigonometric functions conversion.

Gauss meters can generally measure DC and AC magnetic fields, with units that can be switched to display either Gaussian units Gs or international units 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 is required, and the display screen will display real-time magnetic field values and polarity

When it is necessary to capture the peak magnetic field and corresponding polarity during the measurement process, the hold function needs to be used.

As shown in the following figure, the display screen will display "hold", and the displayed values and polarity are the captured peak magnetic field and its corresponding polarity. If there is no display, it is the real function. You can also switch to the AC magnetic field testing mode using the MODE button, as shown in the screen below with the "~" symbol

Precautions for using a Gaussian meter:

When using a Gauss meter to measure the magnetic field of a meter, 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 fixation of the measuring point and to ensure that the probe is tightly attached to the measuring surface and is level with the measuring surface, but do not press hard.

2. Both sides of the Hall chip can sense, but the values and polarity are different. The scale surface is for easy measurement and cannot be used as a measurement surface. Non scale surfaces are the measurement surface.

Gauss meters measure the magnetic field intensity Bz on the default vertical measurement plane. The following figure is a simulation diagram of a regular Z-axis magnetized magnet. It can be seen that the magnetic field is a vector, and the magnetic field intensity on the Z-axis can be considered as Bz=. Due to the shortest magnetic circuit path at the edges, the magnetic field lines at the edges will be denser, and the magnetic field intensity B will be stronger than the center. However, Bz may not always be stronger than the center, but it is only a limitation of the area measured by the Hall chip, Generally, the strength of the measured corner magnetic field is stronger than the center, at least not lower than the center magnetic field.

It should be noted that when the magnetization direction is different, even on the same measurement surface, the difference in measurement values is very large.

For dynamic measurements or the need to fit the magnetic field at different measurement positions into waveform curves, a magnetic field scanner is needed. It still needs to measure through a single direction or three-dimensional Hall chip, and then output the magnetic field measurement curve by designing the measurement trajectory and data acquisition.