Piezo-actuator`s axial position testing method, involves determining axial position of actuator relative to housing by position measurement based on parts of laser beams reflected from housing and actuator, respectively

摘要

The method involves producing a laser beam (11) and directing the beam onto a reference surface (12) of a housing (8). A part of the beam reflected from the reference surface of the housing is received. Another laser beam (13) is produced and directed onto a reference surface of a piezo-actuator (9). A part of the beam (13) reflected from the reference surface of the actuator is received. An axial position of the actuator relative to the housing is determined by a position measurement based on the parts of the laser beams. An independent claim is also included for a device for testing the axial position of a piezo-actuator in a housing, during the operation of the piezo-actuator.