Why is the Gaussian data different for each test of the same magnet?

Because we mostly use Gauss meter or Tesla meter to measure the surface magnetism of the magnet, which is the value obtained by measuring a certain point of the magnet, that is, it is difficult to put the probe of the Gauss meter in the same position every time you measure, so the surface magnetism data will be different, not to mention the values of N pole and S pole. Generally, magnet manufacturers will take the maximum surface magnetic value, that is, there will be a big gap between the position of magnet pole and the surface magnetic measured at the central point. Some customers will indicate how much the central magnetic force needs to be.

To sum up, the surface magnetism of the magnet is related to the magnetic energy product, shape, size and thickness, as well as the brand of the Gauss meter, the package thickness of the probe and the measurement position.

So it's not that the magnetic data of the meter is different, it means that the quality of the magnet is not good.