How is the quality of a magnet measured?

The quality of a magnet is represented by the strength. There are several factors that establish the quality of a magnetic material that will subsequently alter the magnetic field strength capability. The factors that we will have to take into account are size, shape, grade, and location.

Nowadays it is possible to measure the quality of magnetic fields of a magnet due to magnetic measurement processes. In the following, we will explain several measurement methods: 

• Nuclear magnetic resonance can measure the magnetic field with an absolute precision of 0.1ppm, to measure the field must be stable and homogeneous. In case you want to measure inhomogeneous fields, small gradient coils can be used.

• The gaussmeter is an instrument that is responsible for checking the flux density, so it is the meter of the magnetic field.

• The magnetometer is an instrument that is responsible for determining the strength found in the magnetic field.

• The pickup coils are the most commonly used to qualify the quality of the magnetic field.

• Hall probes are sensors intended for the measurement of large magnetic fields.

The quality of a magnet is made up of two parts: the letter and the number.

As for the number appearing in quality, it refers to the strength, in other words, the higher the number, the greater the strength of the magnet.

The letter we find in the quality of a magnet refers to the maximum temperature to which it can be subjected to work.

- M = 100ºC

- H = 120C

- SH = 150ºC

- UH = 180C

- EH = 200ºC

In addition to the above acronyms, we can also find the N which refers to Neodymium. As we can see in the following example the Ni refers to the coating.

To determine whether the magnetic field of a magnet is stronger or weaker, we must observe the distance of the field lines. On the other hand, the strength of magnetization of a magnet does not depend only on the magnetic material, but also on the size of the magnet, and the intensity of the magnet increases as the magnet's dimensions increase. In the same way, the quality will depend on the care we give to the magnet in question, for instance not to subject it to a higher temperature than recommended, nor to store it incorrectly.