abertura del diafragma
/ˌaβeɾtˈuɾa pˌaɾa el ˈkambjo ðe ˈɣases/
n
English: aperture diaphragm · 孔径光阑
Significado：Device with an opening whose diameter can be changed to narrow or widen the diameter of the electron beam.
English: aperture diaphragm · 孔径光阑