[[35C Alignment Procedures]] ## Aperture Alignment - Start with the objective aperture inserted ([[SEM objective aperture size|there are 3 sizes]]) - Focus the image - Center a recognizable specimen inside the aperture - Defocus (medium focus knob counterclockwise) - If the image stays centered, the aperture is aligned - If the image moved off center, use the aperture X and Y knobs to re-center it - Repeat at higher magnifications ### Flowchart ![[JEOL 35C Operating Instructions#Aperture Centering]]