4
2. 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.
3. Plug cord into a standard 120 volt AC three-wire grounded electrical outlet. Push rocker switch
located on base to ON position. In case of equipment malfunction, see “Troubleshooting” located at
back of this manual.
4. Rotate focus knobs to move stage down (away) from objectives as far as possible.
5. Place specimen slide, cover slip facing up, on stage with specimen centered over condenser lens in
middle of stage.
6. Rotate disc diaphragm to position the largest aperture under the hole in center of stage.
7. 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.
8. While looking through the eyepiece, rotate focusing knobs until specimen comes into focus. If image
does not appear in field of view, move specimen slide slightly on stage until image appears in field of
view.
9. Turn the disc diaphragm, observing that different apertures affect the sharpness of the image. Turn
diaphragm until sharpest possible image is obtained. When turning the disc diaphragm, you should
hear a click as each aperture comes into proper position under the hole in center of stage. If aperture
is not properly positioned, you will observe shadows in the field of view when looking through the
microscope.
10. Changing magnification
A. Note that each of the three objectives have a different color ring. This permits the teacher to
instruct the class to switch magnifications by referring to the color of the ring.
B. Total magnification obtained with each objective lens is determined by multiplying the
magnification of the eyepiece times the magnification of the objective. Keep in mind that as
magnification is increased, field of view (area of the specimen seen when looking through the
microscope) decreases. You will find that you use the lower magnifications at most times.
Always use the lowest magnification (4x objective) when first focusing on a new specimen slide,
as this low magnification provides the biggest field of view, thus making it easier to find and
position the specimen within the field of view.
10x eyepiece x 4x objective = 40 times mag. (biggest field of view), field size 4.5mm
10x eyepiece x 10x objective = 100 times mag. (smaller field of view), field size 1.8mm
10x eyepiece x 40x objective = 400 times mag. (smallest field of view), field size 0.45 mm
C. 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.
