- 4 -
Optical characteristics of the microscope (approximated values of magnification factors
and field of views) with use of each pair of the interchangeable eyepieces are presented
in Table 1.
Table 1 - Optical characteristics of the microscope
Characteristics of the
microscope
Magnification
of microscope.
Field of view,
mm
Field of view,
mm
Magnification of
eyepiece,
Magnification
of objective part
10
x
20
x
10
x
20
x
10
x
20
x
0.5
1.0
2.0
3.0
5.0
5
10
20
30
50
10
20
40
60
102
40
20
10
6
4
25
12
6
4
2.5
24
12
Approximate value of interim magnifications is defined as
Г
m
=
β
lens part
x
Г
eye
;
where
Г
m
is the microscope magnification;
β
lens part
is the lens part magnification (Head lens + zoom system)
Г
eye
is eyepiece magnification
Values of
β
lens part
are noted in the scale of the handle 3 of magnification changing
1.4.2. Zoom system
IN order to slightly change the microscope magnification in each of two optical tracts
forming a stereo imagery there is designed a zoom system that consists of two
immovable components and two movable ones. Movable components are being shifted
by guiding elements (clutch pins) with a complicated curvilinear profile. Clutch pins are
moved by handles 3; range of shifting is limited by stoppers located inside the body.
Attention!
1.
Turn the handles 3 smoothly, do not apply jerky forces in the extreme
positions.
2.
Do not turn the handles 3 in mutually antithetic directions.
1.4.3. Head lens
The lens B is attached to the body
Г
by a screw joint and when in operation shall be
tighten to stop.
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4 OPERATION PROCEDURE
4.1 General instructions
Place an object to the operating table of the microscope. Rotating the optical head per
the stand 16 set an approximate operating distance from an object to the head lens. Fix
the setting of the optical head using the fixation handle 14. Switch on the illumination.
Focus the microscope on an object by rotation of the handle 13 at that the handles of
magnification changing shall be set in a position correspondent to the maximum
magnification (figure 5 on the handle 3).
Move the handle 3 to another extreme position correspondent of the minimum
magnification of the zoom system at that time an image in the extreme position shall be
sharp. Any insignificant defocusing that may be occurred at interim values of the zoom
system magnification are compensated by vertical shifting of the microscope optical
head using the handles 13.
4.2. Operation 10
x
eyepiece with scale
The eyepiece has the diopter adjustment mechanism. In focal plane of the eyepiece
there is set scale factor with step 0.1mm.
In order to roughly assess a linear dimensions of an object one of the eyepiece tubes of
the microscope shall be set 10
x
eyepiece with scale. Using the dioter alignment
mechanism of the eyepiece there should be obtained a sharp image of the scale. Then
turning the handle 13 of focusing system one shall align a sharp image of the object. . In
the conversion table 2 there is noted how one scale factor is correspondent to a
dimensional value of an object at the microscope magnification.
Table 2 - Conversion table of the microscope magnifications
Magnifications in approx. numbers
noted on the handles of the zoom
system, times
One scale division 0.1mm corresponds a
measurement on an object
0.5
1
2
3
5
0.2
0.1
0.05
0.03
0.02
In order to determine approximate dimensions of an object (its linear dimensions) it will
suffice to count the number of the division of the scale which are laid in the measured
section of the object and multiply the obtained result by the number indicated in the
conversion. Table corresponding to the magnification of the microscope at which the
measurement is being performed.
