Examining the load-travel characteristic curve of solenoids and proportional magnets effectively provides a function test for electromagnetic actuators and is used mainly for final inspections. This curve allows the principal operating characteristics to be identified, while the load-force curve shows whether the actuator is applying the required force within its operating range at a fixed current level. The hysteresis provides information about friction resulting from the quality of the mechanical parts.
The load-current curve is mainly checked in connection with proportional magnets to establish whether the actuator applies the necessary force within a current range at a defined armature position. The ideal curve is a linear relationship between load and current around the operating point.