Bresser BioScience Mode D'emploi page 10

5. Adjustable Abbe condenser (Fig. 7)
Fig. 7a
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The condenser is moved up or down via tur ning the up-down
knob (1). For centering, the condenser centering scr e ws (7) are
used. The condenser can be taken down easily if one uns-
crews the condenser holding scr ew (2). The place for a filter
plate is on the filter seat (6).
6. Power switch and adjustable brightness (Fig. 7)
Turn on the power switch (3). Adjust the light contr ol (4) until
the image can be observed comfortably . N ote: Don't let the
light control at the position of maximum brightness for a long
time. That reduces the life-span of the lamp.
7. Köhler illumination (Fig. 7)
The Köhler illumination is the optimal microscopic illumination
and ther efore standar d for scientific r
microphotography. One gets it using the fixed field diaphragm
and the height- and center-adjustable Abbe condenser:
a) Using the condenser up-down knob (1), move the
condenser (Fig. 2, No. 3) to the highest position, right under
the stage.
b) Turn on the power switch (3) and focus the object.
c) Shut the field diaphragm (Fig. 6) as close as possible. If the
image of the field diaphragm lies out of the field of view
move it into the field using the condenser centering scr ews
(Fig. 7).
d) Using the condenser up-down knob (1), change the height
of the condenser, until the image of the field diaphragm is
clear.
e) Using the condenser centering scr ews (Fig. 7), center the
image of the field diaphragm in the field of view .
f) Open the field diaphragm so widely , that its edge has only
just left the field of view and this field is complete
illuminated. It may be, that you have to center the
condenser a little bit again. N ow
diaphragm, which is described in the next paragraph.
B G F
Fig. 7
esearch and
, adjust the apertur
8. Aperture diaphragm (Fig. 8)
Fig. 8
The aperture diaphragm lever (Fig. 7, No. 5) can be tur ned in
order to open or close the apertur e diaphragm. Remove the
eyepieces and watch thr
centering, the condenser centering scr ews (Fig. 7, No. 7) ar e
used when the diaphragm image is eccentric with the
objective pupil (1). T urn the apertur e diaphragm lever for
getting a good resolution and contrast perception. Usually, the
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diameter of the aperture diaphragm image (2), which has to be
adjusted, is 70-80 percent of the objective pupil.
9. Exchange of the lamp (Fig. 9)
F
Fig. 9
a) Switch off the power switch and pull out the plugs of the
power cor d fr om mains socket and fr om mains in at the
microscope (Fig. 1, No. 7).
b) Incline the micr oscope, loose the fixing scr ew (3) of the
lamp door on the middle part of the bottom and open the
, lamp door; so, you remove the lamp baseboard (1) from the
bottom.
c) Pull out the old lamp (4) fr om the lamp base (5). Be car eful,
as the lamp may be hot!
d) Insert the new lamp (4) into the lamp base (5). N otice the
properly touching; take care not to touch the lamp with bar e
fingers. E. g., use the pr otective envelope of the lamp or a
tissue, in order to grasp the bulb.
e) Reinstall the lamp door (1) with lamp base boar d (5) on the
bottom with the screw (3).
f) After mounting the lamp well, plug in the power cor d , turn on
e the power switch, tur n the objective lens into the light path,
adjust the condenser upwar ds and downwar ds, and make
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70-80%
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ough the eyepiece tube. For
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