Download Print this page

Mechanical Maintenance - National 447TBL Instructions Manual

Stereoscopic microscopes

Advertisement

E. Looking through left side of microscope with left eye, turn diopter adjustment collar located on left
eyepiece until left image is sharp.
relationship to the index mark on the eyepiece tube.
You have now adjusted the microscope for your personal vision. When viewing other objects of
various sizes, you should not have to make further adjustment of the diopter, and will need only
to adjust the focus knobs. If other users change the diopter setting for their vision, you need only
to return the diopter scale to your setting in order for it to once again be adjusted for your vision.
9. For optimum sharpness of image in the entire field of view, it is important to position your eyes at the
correct point above the eyepieces. Looking through both eyepieces, slowly move your eyes towards
eyepieces to a level where clarity of the entire field of view is achieved. After a brief period of viewing,
you will easily find the best point for your vision.
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 store, is good source of 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 distilled water or 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.

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.
To adjust, observe that stem of focus knob on one side of microscope has a tension adjustment
collar with four small holes. Only one of these holes contains a small set screw. Using a small
jewelers screwdriver, loosen this set screw. Your microscope was supplied with a small pin
spanner wrench having one prong. Insert pin of the wrench into one of the holes, turn collar
clockwise to tighten tension, counter-clockwise to loosen tension. In the event you have misplaced
the wrench, a large rubberband placed around the collar will permit you to grip the collar and turn
it by hand in order to accomplish the same adjustment. After adjusting, tighten the small 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.
Note the scale on the diopter collar and its position in
Page 5

Advertisement

loading

This manual is also suitable for:

446tbl448tbl446tbl-10