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A16.1065
3.6 Adjusting the Transmitted
Illumination Aperture Diaphragm
Insert a centering telescope in the eyepiece
tube, adjust the focal length, and view the
objective pupil plane (a bright circle) and the
aperture diaphragm image. Adjust the
aperture diaphragm so that the size of the
diaphragm image is 70-80% of the size of
the objective pupil plane.
Aperture diaphragm is designed for the
adjustment of numerical aperture, not the
dimmer. Typically, adjusting the aperture
diaphragm to 70% to 80% of the pupil of the
objective will result in an appropriate
contrast and a favorable image. The iris
aperture adjusting handle is marked with the
aperture of the diaphragm.
3.7 Nosepiece
Turn the nosepiece until it clicks in place,
stays in the specified position, can switch the
objective.
Before rotating the converter, check the
objective height to prevent collision with
specimens or stage.
Normally, the objective is mounted by
rotating the nosepiece clockwise (from
above
the
nosepiece)
increasing
magnification in turn.
CAUTION
Be careful when changing the objective.
The objective may collide with the
specimen, because of the short working
distance of specimen observation.
Aperture diaphragm
open/ close lever
Aperture diaphragm image
Objective pupil plane
70-80%
100%
