Optika Italy B-510 Serie Manuel D'instructions page 46

11.3 Phase Contrast Observation (PH)
1. Center the condenser as already described in the chapter
10.9.
• This condenser does not have a swing-out lens, so the
operation described in step 2 is not necessary.
2. Raise the condenser almost until the front lens touches the
bottom of the slide (upper end stop).
• Phase contrast observation requires the condenser
to be positioned higher than the position used for the
brightfield. This is not a defect.
3. Rotate the condenser turret to insert the "10/20" position.
• By inserting any phase ring, the aperture diaphragm
opens automatically. This is a desired effect and should
not be considered a defect.
4. Insert 10x objective into the light path.
5. Place a specimen on the stage and focus.
6. Remove one eyepiece and insert the centering telescope.
(Fig. 79)
7. Rotate the upper part of the centering telescope until the two
phase rings (one dark and one bright) visible in the telescope
are in focus. (Fig. 80)
8. Using centering screws on the condenser ① (Fig. 81), center
the phase rings to make the bright ring ② be concentric to
the dark ring ③. (Fig. 82)
9. Insert 20x objective (do not rotate the condenser turret) and
check the centering of the two rings.
10. Repeat the same operation with other objectives to check
the ring centering: 40x objective – turret position "40", 100x
objective – turret position "100".
• With 40x and 100x objectives it may be useful to slightly
raise or lower the condenser, starting from the upper
end stop, to obtain a better projection of the phase rings.
This is not a defect.
11. At the end remove the centering telescope, reinstall the
eyepiece and begin observation.
• With the 4X objective, the condenser could have a dark
halo at the periphery of the field of view. This is not to be
considered a defect.
CONDENSER
PHASE RING
(BRIGHT) ②
OBJECTIVE
PHASE RING
(DARK) ③
Page 46
UPPER PART OF
CENTERING
TELESCOPE
F ig. 79 F ig. 79
F ig. 80 F ig. 80
①
F F ig. 81 ig. 81
F ig. 82 F ig. 82