4
4.4 Examining Specimen at High Power
When examining a specimen at high magnification, position the slide
so the feature is centered in the field of view. If the feature you want
to observe appears to the left of the field of view, move the slide left
to center it. If the feature you want to observe appears to the right of
the field of view, move the slide to the right.
By rotating the nosepiece, bring the next higher power objective into
viewing position. The objective is properly aligned when the nosepie-
ce clicks into place.
4.5 Oil Immersion Technique
To utilize the full numerical aperture of an immersion objective (with
inscription “oil”), oil is added to both the objective and specimen using
the following procedure:
1. Focus on the specimen with a lower power objective (40x).
2. Put a drop of immersion oil on the specimen slide.
3. Turn the nosepiece to bring the immersion objective into the
light path, and focus with the fine adjustment knobs.
Care should be taken to prevent bubbles from forming in the oil, sin-
ce they will deteriorate the lens performance. Simply reapply the
immersion oil if bubbles form.
IMPORTANT:
After each use of the 100x objective, use a lens tissue
or soft cloth to wipe off all traces of oil from the objective and the sli-
de.
5.0 Care of the
Microscope
5.1 General
It is important to keep all optical components clean to obtain the best
optical performance. Keep a dust cover on the microscope when it is
not in use.
The objectives are easily subjected to dirt, dust and oil. Whenever
lack of contrast, cloudiness or poor definition is encountered, careful-
ly check the condition of the front objective lens with a magnifier. To
assure all objective lenses are clean, periodically examine them with
a magnifying glass.
If an optical surface becomes badly coated with dust or dirt, use an
air-filled syringe or soft brush to remove it before wiping the surface
clean.
IMPORTANT:
Clean optical surfaces with a lint-free cloth, lens tissue
or a cotton swab moistened with methanol or commercially availa-
ble glass cleaner. Avoid excessive use of solvents. Interior surfaces
can be loosened or badly damaged if solvents seep in around the len-
ses.
The higher magnification objectives use a small front lens. The surfa-
ce of this front lens can be cleaned with a small cotton swab. Dampen
the cotton tip with methanol and squeeze it dry. Wipe the front lens
lightly. Make sure that the cotton tip contacts the lens surface. Check
the objective with a magnifier after the cleaning.
IMPORTANT:
If it is necessary to remove the viewing body, DO NOT
TOUCH the outer surface on the underside of the viewing body. Finger
prints on this surface will reduce the image clarity. This lens can be
cleaned in the same manner as objectives and eyepieces.
5.2 Mechanical Maintenance
All non-optical components of the Leica BM E Compound Microscope
can be cleaned with soap and water. Avoid using all other harsh sol-
vents or acetone-based products when cleaning.
The Leica BM E Compound Microscope requires only routine main-
tenance. Neither the focusing mechanism nor the mechanical stage
require lubrication. Contact your Leica customer service representa-
tive for more information.
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