1. The calculated result is the surface magnetic field intensity under the condition of the test point is in the center of the wafer;
2. The size of the surface magnetism to NdFeB magnets with same dimension is only relevant to residual magnetism, so other marks outside of N-grade such as H, SH, UH and others have same calculation results with ā;
3. 3.During practical test, in case the residual magnetism Br is poor in consistency, there might be relatively difference to the measured value.