http://virtual.itguiucedu/training/em_tutorial A Look Inside the column Column Electron gun Gun alignment control Pneumatic air lock valve Condenser lens I+ Objective aperture canning coil Objective lens Motorized stag tage Sarnple Chamber http://www.youtube.com/watch?v=c7evtnvhn-satw1:10-2:10insidethecolumnA Look Inside the Column Column http://www.youtube.com/watch?v=c7EVTnVHN-s at~1:10-2:10 inside the column http://virtual.itg.uiuc.edu/training/EM_tutorial