5
MAINTENANCE
WARNING: For your own safety, turn switch off and remove plug from power source before
maintaining your microscope. If the power cord 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 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.
C. To clean eyepiece lenses, do not remove from eyepiece tube. 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. Clean front lens element only, following same procedure.
2. MECHANICAL MAINTENANCE
The only mechanical adjustment you might ever require is the tension of the focusing mechanism.
This has been adjusted at the factory, but over the course of time it may loosen and cause the
head of the microscope to slip downward on the focusing block.
The knurled 6mm wide by 35mm diameter tension adjustment collar is located between arm and
coarse focus knob on right side of microscope. With the supplied “L” hex wrench, loosen the set
screw located in only one of the four holes on tension adjustment collar. Using supplied rod
wrench turn tension adjustment collar clockwise to tighten tension, counterclockwise to loosen
tension. After adjusting tighten the set screw 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 head of microscope to drift downward from its own weight and
cause the microscope to “drift” out of focus.
3. ELECTRICAL MAINTENANCE
The extent of electrical maintenance, by other than a qualified technician, should be bulb replacement.
BE CERTAIN TO TURN SWITCHES OFF AND REMOVE PLUG FROM POWER SOURCE OUTLET
BEFORE CHANGING BULBS.
A. To replace top bulb (National bulb #800-423)....remove light shade by rotating in a counter-
clockwise direction. Remove light bulb by firmly grasping edge of reflector and pulling straight out
from bi-pin socket. Note that the socket holds bulb securely, so you might have to pull rather
firmly. Using a cloth, hold new reflector bulb and gently push new bulb in bi-pin socket. Replace
light shade.
B. To replace bottom bulb in stand (National bulb #800-138)....remove perforated lamp cover plate
located on bottom of base by removing the large black knurled locking screw then push cover
plate to the rear of base. It will be necessary to cut the white cable tie wrapped around base of
lamp (this tie is used to secure lamp during shipment and it is not necessary to replace). Holding
fluorescent lamp with a cloth, gently pull lamp straight out from socket. Push new lamp into place
in same manner and replace cover plate and locking screw.
