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

10.3 Phase contrast observation (PH)

1. Center the condenser as already described at
page 19.
2. Rotate the condeser 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 ② be concentric to 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. Repeate 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.
CONDENSER
PHASE RING
(BRIGHT)
②
OBJECTIVE
PHASE RING
③
(DARK)
Page 24
Fig. 28
Fig. 29
①
Fig. 30
Fig. 31