5
3. To change magnification:
a. Rotate revolving nosepiece to position 10x objective into optical path. Some slight adjustment
of focusing knob may be required.
b. Rotate revolving nosepiece to position 40x objective into optical path. Some slight adjustment
of focusing knob may be required.
Note: Take care when rotating 40x objective into place. This is the longest lens and has a
spring retractable mechanism which retracts slightly into its housing if the front of the lens
comes in contact with the specimen slide while focusing the microscope. This prevents
damage to the lens or slide.
MAINTENANCE
WARNING: For your own safety, turn switch to OFF position 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.
A. OPTICAL MAINTENANCE
1. Do not attempt to disassemble any lens components. Consult an expert technical service
company when repairs not covered by these instructions are needed.
2. Prior to cleaning any lens surface, brush dirt and lint off lens surface with camel hairbrush or
compressed air. Use of air in a can, available at most computer stores, is good source of clean
air.
3. Do not remove eyepiece lens or objective lenses from microscope. Clean only the outer lens
surface by breathing on lens to dampen surface, then wipe with lens paper or cotton swab. Avoid
wiping lens surface while dry, as lenses are scratched very easily.
B. MECHANICAL MAINTENANCE
1. Stage stop adjustment: Stage stop has been pre-adjusted at the factory, and should not require
readjustment.
2. Metal parts: Use a clean, damp cloth to remove dust or dirt from metal part followed by a dry cloth.
C. ELECTRICAL MAINTENANCE
1. Replacement of bulb (National #800-001) To open the illuminator field lens housing use 0.90mm
“L” type hex key wrench supplied with your microscope to loosen hex screws on lens housing.
Remove lens housing to expose LED “bulb”. Remove bulb by grasping the plastic base of bulb
and gently pulling straight up. Insert new LED “bulb”, replace lens housing and tighten hex screw
to secure lens housing in place.
2. Replacement of fuse (National #801-160) The fuse is located at right rear side of microscope
base. To remove fuse from holder, insert a 6mm screwdriver blade into slot located in rear of
fuse holder cap. Slightly depress and rotate screwdriver ¼ turn in direction of arrow to release the
fuse. Pull cap and fuse out of fuse holder. Insert proper 0.5 amp fuse into fuse cap. Insert fuse
assembly into fuse holder. Using screwdriver rotate fuse cap assembly in opposite direction of
arrow until guide slot engages, depress fuse cap and rotate ¼ turn to lock into fuse holder.
