1
Preparation for Centration
Step: 1
Disengage the Analyzer and Bertrand Lens by switching the operating
lever to “O” position as shown in Fig. 13. Fully open the aperture
diaphragm of the condenser by rotating its ring to the extreme left.
Lower the microscope stage. Place a POL specimen on the stage. Swing
in 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 specimen section into focus by
lowering down the sage.
2
Koehler Illumination Centration
Step: 2
Swing in the 10x objective into working position. Flip in top lens of Flip Top
condenser in light path. Close the Koehler field diaphragm so that its
closed iris leaves image is present within the field of view. Use the
condenser focusing knob to bring the image into sharp focus. Operate the
condenser centering screws simultaneously to Center the image of the
field diaphragm Ref. Fig. 22 (a), (b), (c). After centration open the field
diaphragm until the Image (iris leaves) disappears just beyond the field of
view.
3
Flip Top Abbe Condenser Centration
Step: 3
Look through 10x Objective & Eye Pieces cross hair scale. Close the
condenser diaphragm until approximately 20-25% of the iris leaves fill the
field of view. Adjust the centering of the diaphragm by maintaining
condenser centering screws simultaneously with reference to Eye Piece
cross hair scale Ref. Fig. 23 (a).
Note: When changing the objectives, adjust the condenser field
diaphragm with respect to each objective.
CENTRATION
10
Fig. 23
Lx POL
Fig. 22
Fig. 23 (a)
(a)
(b) (c)
R
R
Lx POL
22
22
22
22
17
