National 130, Instructions Manual

Page: 4 / 8

4
OPERATION
1. Place microscope directly in front of you in a manner which permits you to comfortably look into the eyepiece. Note
that the head of microscope rotates 360
º
, permitting you to operate the microscope from the front or from the back,
whichever is most convenient for you. It also permits convenient sharing of microscope by more than one user, by
simply rotating head, without needing to move entire microscope. Most users will position the microscope with the
arm facing them so that focusing knobs are most convenient to reach.
2. Assure that light is available for illuminating the specimen.
a. For mirror models, assure that there is a good nearby source of overhead light, tabletop lamp or reasonably bright
natural light. Position the plano (flat) side of mirror upward. Looking through the microscope eyepiece, tilt mirror
(mirror tilts on either of two axis) until light appears to fill the entire field of view.
b. For electric illuminator models, make certain that the main voltage of your microscope corresponds to the
voltage of your power outlet, either 120v or 220v. Insert microscope plug into matched voltage outlet. Flip
switch located on base to “ON” position. In case of equipment malfunction, see “troubleshooting procedure”
located at back of this manual.
3. Rotate coarse focus knobs to move stage down (away) from objective lens as far as possible.
4. Place specimen slide, cover slip facing up, on stage with specimen centered over condenser lens in middle of stage.
5. Rotate disc diaphragm until largest aperture is positioned beneath condenser in center of stage.
6. Turn the objective turret until the 4x (smallest) objective lens “clicks” into position in the optical path. Note that each
time you change from one objective lens to another you should turn the turret until you hear the “click”, which
indicates that the lens is properly indexed in the optical path.
7. While looking through the eyepiece, rotate coarse focusing knobs until specimen comes into focus. If image does not
appear in field of view, move specimen slide slightly until image appears in field of view.
8. Adjust fine focus controls until specimen is in sharp focus.
9. Turn the disc diaphragm, observing that different apertures affect the sharpness of the image. Turn diaphragm until
sharpest possible image is obtained. Note that when turning the disc diaphragm, you should hear a “click” as each
aperture comes into proper position under the condenser lens. If aperture is not properly positioned, you will observe
shadows in the field of view when looking through the microscope.
10. Changing magnification
a. Magnification is changed by rotating objective turret until different objective lens is moved into optical path.
Always turn turret until you hear the “click”, indicating that lens is properly indexed. Otherwise, you will not be
able to see anything when looking through the microscope.
b. Standard lenses provided with your microscope are a widefield 10x eyepiece (two eyepieces supplied with
models 132 and 139). 4x. 10x, and 40x objectives. The 40x objective lens has a special spring retractable
mechanism which retracts slightly if front of lens comes in contact with the specimen slide. See chart below for
specifications on objectives.
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