12100 POLARIZING MICROSCOPE SERIES
UNITRON
®
15
ADJUSTMENT & OPERATION
(continued)
Centration
When using a polarizing light microscope it is
desirable for the object under study to remain
centered in the field of view as the stage is rotated.
The components of your microscope were
adjusted for optimal centration prior to shipment.
In the event the pre-adjustment is lost, it can be re-
established following procedure below.
This is a two part procedure involving the
STAGE and the OBJECTIVES:
STAGE
1. Place a specimen under the stage clips.
2. Remove analyzer from the optical path.
3. Focus on the specimen with 10x objective. One
eyepiece must have a crosshair reticle.
4. Select an easily recognizable feature and move
the slide so the feature is at the intersection of
the eyepiece crosshair.
5. Loosen the stage-rotation clamp thumbscrew
(knurled screw at the front of the stage).
6. Insert the two stage-centering tools.
7. Rotate the stage 180 degrees.
8. If the feature selected in Step 4. above shifts
away from the center, simultaneously turn the
two stage- centering screws so that the
eyepiece intersection point of the crosshairs
moves halfway towards the feature.
(
NOTE
: The reticle is not actually moving, the
motion is the object moving beneath the objective.
Thus the apparent motion of the reticle in relation
to the feature is an illusion. However, it is common
to refer to the reticle as “moving toward the
feature”).
9.
It may be necessary to repeat steps 7 and 8
several times. The factory specification for
centration is approxi/- 2 div. of the
Measuring eyepiece horizontal scale.
10. Remove the two stage-centering tools when
satisfied with the centration.
11. Tighten the stage-rotation clamp thumbscrew.
The stage now rotates on the optic axis of the
10x objective. Do not move the specimen.
OBJECTIVES
NOTE:
The following procedure assumes the
stage has been centered to rotate about the
center of the 10x field of view. See previous
section on page 14 for instruction.
The design of the 12100 Polarizing Microscope
allows the remaining objectives to now be
preci
sely aligned with the stage’s new axis of
rotation. This advanced feature assures the
object under study remains in the center of the
field of view as different magnifications are
used.
1. Select the 20x objective.
2. Insert the two objective-centering screws
into the access openings in the nosepiece
above the objective.
3. Turn the objective-centering screws to move
the crosshair intersection to the feature
selected in step 4 of stage centration
procedure (see previous section).
4. Rotate the stage 180 degrees.
5. If the feature shifts away from the center,
simultaneously turn the two objective-
centering screws so that the eyepiece
intersection point of the crosshairs moves
halfway towards the feature.
6. It may be necessary to repeat this steps
several times. When the feature rotates in
the center of the field of view, the 20x is
properly centered.
7. Remove the two stage-centering tools and
proceed to center the remaining objectives
using the same procedure (1.
– 6. above).
