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6
MAINTENANCE
WARNING: For your own safety, turn power switch off, remove plug from AC power source and remove charging cord
from microscope input before maintaining your microscope. If the power cord, recharger is worn, cut or damaged in
any way, have it replaced immediately to avoid shock or fire hazard.
1. OPTICAL MAINTENANCE
a. Do not attempt to disassemble any lens components. Consult a microscope service technician when any repairs not
covered by instructions are needed.
b. Prior to cleaning any lens surface, brush dust or lint off lens surface using a camel hairbrush. You can also use an ear
syringe or canned compressed air, such as that sold by most computer stores.
c.
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
a. The rack stop screw has been pre-adjusted at the factory and should not require re-adjustment. However, if you do
attempt re-adjustment, note the following procedure.
Loosen round knurled locking nut by turning counter clockwise then, using a 2mm “L” type hex key wrench, loosen
rack stop socket set screw. With fine focus adjustment at mid-range, focus on standard slide until sharp image is
obtained. Rotate rack stop set screw in clockwise direction until tight, tighten locking nut..
b. Coarse focus tension adjustment prevents the stage from drifting down from its own weight and causing the image to
move out of focus. This has been adjusted at the factory, but over the course of time it may loosen and cause the
stage of the microscope to slip downward on the focusing block.
The tension adjustment collar is located between arm and coarse focus knob on right side of microscope. Using a
0.9mm “L” type hex key wrench, loosen the set screw located in the hole on tension adjustment collar. Turn collar
clockwise to tighten tension, counter-clockwise to loosen tension. Use of a wide rubber band will provide a better grip
on the tension adjustment collar. After adjusting, tighten the setscrew to lock collar in place.
NOTE: It is recommended that you leave the tension as loose as possible for ease of focusing, yet not so loose that it
permits the stage of microscope to drift downward from its own weight and cause the microscope to “drift” out of focus.
c.
Metal parts: Use a clean, damp cloth to remove dust or dirt from metal parts, followed by a dry cloth.
3. ELECTRICAL MAINTENANCE
a. The extent of electrical maintenance, by other than a qualified technician, should be LED replacement, battery
recharging and battery replacement. Before maintenance, be sure that recharger is not connected to microscope.
b. Recharging batteries:
Plug output cord from battery charger into DC recharging socket located on back of microscope base. Your automatic
switching recharger operates on 100 to 240 volts AC 50/60 Hz. Plug charger into your AC wall outlet. Battery
recharger is also equipped with an automatic “trickle charge” feature, the red LED indicator lamp located on recharger
will be illuminated when batteries are receiving maximum charge. After batteries are charged, the red LED indicator
lamp will turn to green and charger automatically switches to “trickle charge”. The charger can be left plugged in, but
for safety reasons it is a good idea to disconnect the charger from the AC wall outlet and the output cord from
recharging socket after 12 hours. Batteries and charger may feel warm when charging, and unplugging the recharger
is a safety precaution.