5
Objective Specification Chart
Objective
N.A.
Color Code
Ring
Field of
View
Working
Distance
Magnification with
WF10X eyepiece
Din 4X
0.10
Red
4.5mm
18.5mm
40X
Din 10X
0.25
Yellow
1.8mm
6.4mm
100X
Din 40X retractable
0.65
Blue
0.45mm
0.5mm
400X
c. Also note that each objective has a color ring, which permits you to instruct changes in magnification by referring
to an easily observed color rather than to a number.
d. The microscope has been parfocalled at the factory, which allows easy change from one magnification to another,
requiring little or no adjustment of the fine focus knobs.
e. As magnification is increased, the field of view (area of specimen seen through the microscope) will decrease.
That is why it is easier to find the specific area of interest on the specimen by starting with the lowest 4x objective
lens, before increasing magnification with the 10x or 40x objective lens.
f.
NOTE: Care must be taken when rotating the 40x objective into place. This lens has a spring retractable
mechanism which retracts slightly into its housing if the front of the lens strikes the specimen slide. With fine
focus adjustment at mid-range, the rack stop has been adjusted at the factory to assure the 40x lens will clear the
thickness of a normal specimen slide and cover slip. However, if the rack stop has been improperly adjusted, or if
using a thicker than normal slide or cover slip, moving the 40x lens too quickly or carelessly could cause damage
to the front lens element or to the slide.
g. Do not let the front lens element come into contact with a wet slide surface, as prolonged contact with any
moisture could damage the lens. If lens is exposed to moisture, promptly wipe with soft tissue to remove
moisture.
MAINTENANCE
WARNING: For your own safety, turn switch to OFF position. Remove adapter from the power source and
detach plug from jack located at back of microscope base before maintaining microscope.
1. OPTICAL MAINTENANCE
Do not attempt to disassemble any lens components. Consult a microscope service technician when any repairs not
covered by instructions are needed.
Prior to cleaning any lens surface, brush dust or dirt off lens surfaces using a camel hair brush. Or use air to blow
dust and lint off surfaces. Use of compressed air in a can, available at any computer supply store, is a good source
of clean air.
Do not remove eyepieces or objective lenses to clean. Clean only the outer lens surface. Breath on lens to dampen
surface, then wipe with lens paper or tissue or use a cotton swab moistened with distilled water. Wipe lenses with a
circular motion, applying as little pressure as possible. Avoid wiping dry lens surface as lenses are scratched easily.
If excessive dirt or grease gets on lens surfaces, a small amount of Windex can be used on a cotton swab or lens
tissue. To clean objective lenses, do not remove objectives from microscope. Clean front lens element only,
following same procedure.
NOTE: Fingerprints or other matter on the front lens element of the objective lens is the single most common reason
that you will have difficulty in focusing the microscope. Before having costly servicing done, or before returning to
National for “warranty repair”, make certain to examine the front lens element with a magnifying glass or eye loupe for
the presence of such contaminants. If a microscope is returned to National for warranty repair, and it is determined
that such contaminants are the problem, this is not covered under warranty and National will submit a cost estimate
for cleaning.
2. MECHANICAL MAINTENANCE
