Intrinsic magnetic properties of permanent magnet which including remanence Br, coercivity Hcb, intrinsic coercivity Hcj, and Max. Energy Products (BH)max, is mainly depending on its composition and microstructure, then nothing to do with shape and dimension. However, magnetic parameters which simultaneously affected by shape and dimension, including gauss value, magnetic flux or magnetic moment, are obtaining more attention from users.
Magnetic moment of the permanent magnet is tested by Helmholtz coil and Fluxmeter. Its value is related to remanence Br, dimension, and Pc value of magnet. Magnetic flux and magnetic moment can be transformed into each other via coil constant, thus well suitable for magnetic performance comparison between magnet manufacturers and users.
Dimension and shape of permanent magnet getting smaller and more complicated, respectively, especially high-coercivity sintered Neodymium magnets for consumer electronics. Therefore, it is quite difficult to test their performance via Gaussmeter and Fluxmeter, then the magnetic moment is treated as a sensible choice to collect accurate value with superior repeatability. For permanent magnet with straight B-H curve, their other magnetic parameters like operating flux density Bd, operating field strength Hd, coercivity Hcb, remanence Br, and Max. Energy Products (BH)max is all can be approximately derived from measured magnetic moment. Even relevant deduction method is not as accurate as hysteresisgraph measurement and cannot derive intrinsic coercivity Hcj, its measurement and deduction process are easy and equipment cost is substantially less. In addition, its testing efficiency is well above hysteresisgraph, then well adapted for 100% inspection.
