6. TROUBLESHOOTING
Problem
Darkfield
No definite DF contrast is possible.
The image is not uniformly illuminated.
Unwanted stray light.
Phase Contrast
Phase Contrast cannot be adjusted.
Polarization
Polarization contrast cannot be adjusted.
Cause/remedy
Be sure that a DF objective is being used.
The objective aperture setting is too high:
Maximum 0.7 for condenser S1
Maximal 0.4 for condenser S23/28/40
If necessary, reduce the objective aperture using the iris
diaphragm on the objective.
Check the condenser centering.
The magnification is too weak.
Use a higher magnification.
If necessary, remove the condenser lenses or the con-
denser head.
Clean the specimen and neighboring lens surfaces.
The specimen is too thick, too thin or too brightly stained.
Refractive indexes of the mounting medium and specimen
are identical, so that there is no phase jump.
The cover glass is not placed uniformly.
Check that the correct light ring is positioned.
Check that the correct light slider is positioned.
The S40/0.45 condenser has been switched with the
S80/0.30 condenser.
Open the aperture diaphragm completely.
IMC modulator in IMC position.
Check the centering of the light rings.
Bring the polarizer and analyzer into cross position until
they reach maximum darkness (without specimen).
87
To Next Page
Loading...
