The motorised unit completely replaces the existing final aperture assembly. The system comprises, a precision motorised mechanical assembly, drive electronics and keypad controller, or accessory panel which can be fitted to the SEM console.
Upto five aperture positions can be selected using push buttons, the centre position of the aperture may be adjusted using arrow buttons. Aperture positions are stored in non-volatile memory so that when selecting a new aperture, re-centering is not necessary. Total movement is 10mmx1mm with position reproducability better than 3um. Motorised aperture drives may be supplied for any column with a side entry aperture holder.
An optional RS-232 interface in incorporated for remote operation. Aperture selection may then be controlled from a microscope computer control program, removing the need for an accessory panel or keypad.
Applications include hot cell construction and remote operation (internet microscope).