Leica DM EP Manual De Instrucciones página 4

4.0 Centration
Preparation for Centration
A. Attach the power cord and plug it into a
grounded electrical outlet. Turn on the
microscope with the knurled illumination
control knob on the bottom left side of
the microscope. Set the illumination
control to the lowest setting.
Note: Never use an adapter between the
power cord and the power source; it will
render the microscopes grounding
feature ineffective.
B. Disengage the Analyzer and Bertrand
Lens (optional) by flipping the switches
to the "O" position. Fully open the
aperture diaphragm of the condenser by
rotating its ring to the extreme right.
C. Lower the microscope stage. Place a POL
specimen on the stage. Rotate the 10x
objective into working position. Raise the
microscope stage using the coarse
adjustment knob until you reach its
positive stop. Use the fine adjustment
knob to bring the POL section into focus.
Koehler Illumination Centration
Close the Koehler field diaphragm so
that its iris leaves are present within the
field of view (Fig.1a). Use the condenser
focusing knob to bring the leaves of the
field diaphragm into sharp focus (Fig.
1b). Turn the condenser centering screws
simultaneously to Center the image of the
field diaphragm. (Fig.1c) Open the field
diaphragm until the iris leaves disappear
just beyond the field of view (Fig.1d).
Fig. 1
Leica DM EP
E N G L I S H
Condenser Aperture
Remove an eyepiece and view the back aperture of the
objective. Close the condenser diaphragm until
approximately 20% of the iris leaves fill the field of
view (Fig.2). Replace the eyepiece. Note: When chang-
ing objectives, adjust the condenser field diaphragm to
the corresponding marked location for each objective.
Fig. 2
Objective Centration
Narrow the aperture diaphragm. Retrieve the two
centering keys. Insert the centering keys in the
centering holes above the objective you want to center.
Focus the POL sample.
Move a prominent point of the specimen (Fig. 3 a) to
the center of the crossline. Rotate the stage until the
prominent point of the specimen is furthest away from
the center of the crossline (Pos.1 Fig. 3b). Pos.1 may
even be outside of the field of view. Adjust the image
with the centering screws until the prominent point of
the specimen in Pos.1 is midway between Pos.1 and
the center of the crosslines (Pos. 2 Fig. 3c). Move the
specimen so that the prominent point at Pos.2 is at the
center of the crossline. Check that it stays at the center
of the crossline when the stage is rotated. Repeat the
centering process if necessary. Note: Each objective
must be centered separately.
Fig. 3
4