Surface magnetism, also known as surface magnetic field, refers to the magnetic induction intensity at a

certain point on the surface of the magnet, and the unit is Gauss Gs or Tesla T (1T=10000Gs).

The parameter of surface magnetism is easy to measure. When the size of the magnet is determined, people

often judge the performance of the magnet by comparing the surface magnetism. When encountering some

magnets that are not suitable for routine measurement, particularly large or small, and special shapes,surface  magnetic measurement is particularly important.

But we need to know that the surface magnetism is the value measured by the Gauss meter in contact with a certain point on the surface of the magnet. The measurement point does not cover the entire surface of the product. The surface magnetism of different positions on the surface of the magnet is different, so take a certain point The value to measure the value of the entire face is incorrect For non-multipole magnetized and regular-shaped magnets, the central surface magnetism is generally measured.

The surface magnetism is easily affected by the external environment. When measured in different environments, the measured surface magnetism may be different. For the same magnet, using Gaussmeters from different manufacturers, the measured central surface magnetism may be different. The central surface magnetism of the N pole and S pole of the same magnet is also different. And don't forget that every gauss meter has an error of around 2%. 

It can be seen that the surface magnetic measurement is not objective, and it is not a parameter that can fully reflect the performance of the magnet. Therefore, it is usually not recommended as an evaluation indicator for product transactions.