Phase Contrast Observation (Ph) - Optika Italy B-380 Serie Manual De Instrucciones

11.3 Phase contrast observation (PH)

1. Center the condenser as already described at page 20-21.
2. Rotate the condenser turret to insert the "10/20" position.
3. Insert 10x objective into the light path.
4. Open aperture diaphragm.
5. Place a specimen on the stage and focus.
6. Remove one eyepiece and insert the centering telescope.
(Fig. 28)
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. 29)
8. Using centering screws on the condenser ①, (Fig. 30) center
the phase rings to make the bright ring
the dark ring ③.
9. Insert 20x objective (do not rotate the condenser turret) and
check the centering of the two rings. (Fig. 31)
10. Repeat the same operation with other objectives to check
the ring centering: 40x objective – turret position "40", 100x
objective – turret position "100".
11. At the end remove the centering telescope, reinstall the
eyepiece and begin observation.
• With 40x and 100x objectives it may be useful to slightly
raise the condenser, to obtain a better projection of the
phase rings. This is not a defect.
• 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.
be concentric to
②
Page 24
CONDENSER
PHASE RING
(BRIGHT)
②
OBJECTIVE
PHASE RING
③
(DARK)
F F ig. 28 ig. 28
F ig. 29 F ig. 29
①
F ig. 30 F ig. 30
F ig. 31 F ig. 31