1 ambient temperature. Since sintered NdFeB has a negative temperature coefficient (αBr<-0.13%/°C, αHcj<-0.6%/°C), the instantaneous maximum temperature and the continuous maximum temperature of the use environment will have different degrees to the magnet itself. Demagnetization, including reversible and irreversible, recoverable and unrecoverable.
2 ambient humidity. NdFeB itself is easily corroded and oxidized. Generally, we use surface treatment to protect permanent magnets, but it does not fundamentally solve the effect of ambient humidity on magnets. The drier the environment, the longer the life of the magnet.
How to measure the level of magnetic performance, there are three main parameters:
Residual Induction, the unit of Gauss, is a measure of the strength of the magnetic field provided by the magnet;
Coercive Force, the unit of Oersteds, is a measure of the ability to resist demagnetization;
The magnetic energy product BHmax, in units of Gauss-Oersteds, is a physical quantity that characterizes how much energy can be stored.