kruss MBL2000 Series Operating Manual page 25

7. Phase contrast device
4. Insert one of the condensers with the phase
contrast diaphragm into the microscope
(MML2031 or MML2032)
5. Remove an eyepiece from the tube end and replace
it with a centring telescope.
6. Focus the dark pattern of the phase contrast gap of
the object lens by adjusting the eyepiece of the
centring telescope accordingly.
7. Move the microscope stage with the coarse
adjustment knobs to the highest position.
8. Slowly lower the microscope stage until a sharp
image of the bright pattern of the condenser
annular gap appears.
9. The bright pattern must be adjusted until it is con-
Non-adjusted phase
centric with and overlapped by the darker pattern.
Adjust both centring knobs which are located on the
front of the ring diaphragm holder of the condenser.
The phase annular gap is intentionally made some-
what larger than the image of the condenser dia-
phragm to ensure a complete overlapping and to
Adjusted phase
prevent light from escaping the phase annular gap.
Such a light scattering would affect the contrast.
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7. Phase contrast device
10. Replace the centring telescope with the previously
removed eyepiece.
The microscope can now be used for the examination
of samples with the phase contrast method.
Note!
The use of an additional Abbe transmitted light con-
denser whereby a centring diaphragm is mounted for
the phase contrast method makes it possible to signifi-
cantly reduce the time required for converting between
bright field and phase contrast method.
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