11
STEINDORFF
®
4.2.
Use of the 100XR, Oil Immersion Objective
1.
Focus on the specimen by switching the objectives from the lowest power to highest power.
2.
Before engaging the immersion objective in the light path, place a drop of immersion oil onto
the specimen at the area to be observed.
3.
Turn the revolving nosepiece to engage the immersion objective, then focus using the fine
adjustment knob.
4.
Make sure the oil is free of bubbles. To remove bubbles, turn the revolving nosepiece to move
the oil immersion objective back and forth a few times.
5.
Immersion oil is used in the contact beneath the underside of the slide and the condenser top
lens, and also between the objective and cover slip
6.
After use, remove oil from the objective front lens by wiping with gauze slightly moistened with
an ether (70%)/alcohol (30%) mixture.
4.3.
Darkfield Observation
There are two kinds of darkfield condenser available, one darkfield dry (NA 1.25), one darkfield oil
(NA 1.25~1.36)
Replace the condenser with the darkfield condenser as needed.
If darkfield oil observation is needed, make sure use oil between the condenser and back part of
the specimen slide, and also between the front part of the specimen slide and the objective (oil).
Only in this way, we can get the numerical aperture that is desired.
Open the field diaphragm.
Observe the specimen for darkfield observation.
4.4.
Polarizing Observation
A polarizing kit includes a polarizer and an analyzer.
Hold the upper part of the polarizer and screw
it in the condenser.
Pull out the attachment notch, put the analyzer
in, and put the notch back.
Observe
If the condenser engraving shows a numerical aperture (NA) of 1.0 or higher, the number applies only
when oil is applied between the slide glass and the top surface of the condenser. When oil is not present,
the NA is about 0.9.
Hold the upper part of the polarizer to screw in.
