What are the concepts of the magnetism and the surface magnetic flux density of a magnet? How are they defined? What are the relationships and influences between them?
The surface magnetic flux density of a magnet refers to the surface magnetic induction intensity at a certain point of the magnet. This issue can be explained in two cases:
1. For two magnets with the same shape and size, the magnet with a higher surface magnetic flux density has stronger magnetism.
2. For two magnets with different shapes or sizes, the magnetism of the magnets cannot be simply judged by the level of the surface magnetic flux density.
The definition of surface magnetic flux density:
The surface magnetic flux density refers to the magnetic induction intensity on the surface of the magnet. The surface magnetic flux density data presented on the magnet surface is only a data reflection of the magnet itself to the measuring tool. Since the induction of each measuring tool may not be accurate, there is no definite specification for the surface magnetic flux density of magnet products. The most common way is to enlarge the tolerance range of the data or directly make requirements according to its own products. After all, the data is just an objective manifestation.
Generally, Gaussmeters, also known as Teslameters, are used to measure the surface magnetic flux density of magnets. However, since there is no specific standard for the products produced by each manufacturer, and because the Hall sensing elements on the Gaussmeters are different and the Hall sensing intensities are different, the measured surface magnetic flux densities are also different.
To put it simply: for the same product, if we measure it with a domestic Gaussmeter, and the measured surface magnetic flux density is 3000 GS (GS: unit of surface magnetic flux density), when we change to a Japanese Gaussmeter for measurement, due to the quality problem of the Hall sensing element on the Gaussmeter, the surface magnetic flux density measured by the Japanese Gaussmeter will be about 200 GS higher. Therefore, for a magnet product, its quality cannot be judged simply by looking at the surface magnetic flux density.
