Surface magnetic flux density is proportional to the size of themagnet bars can absorb the smallest particles in the battery, pharmaceutical and other fields of fine iron impurities can cause a great impact, so the choice of the magnet about 12,000 Gauss. Other areas you can use a little low.
magnetic bar in contact with the fluid in the process using the internal magnetic energy will be part of an irreversible loss, loss exceeds the initial intensity of 30% or metal surface coating and stainless steel pipe rupture when worn, then the need to replace the magnet, and not allow leakage magnet magnet continues to work, magnets are generally more brittle surfaces coated with some oil, the environmental pollution is relatively large.