An improved calibration of ferrite permanent magnets in mass-production

The paper presents a method applied for calibration of ferrite permanent magnets in mass-production. The magnetization procedure of the permanent magnet to the saturation level followed by its partial demagnetization using a pulse-generating device is described. An advanced test site controlled by LabView software is presented, with special emphasis on demagnetization voltage determination. With implementation of the appropriate algorithm, the magnet´s operating point can be set to the required tolerance range (below 3%) and within a short period of time, which is important for cost-effective mass-production. The principle is intended to be used for calibration of linearity correctors that are built into CRT computer monitors and TV sets.