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The dark field condenser is a system of lenses inserted into the cylinder. The cylinder is placed inside the microscope body on
the moving ring. This ring is a centering device, which can be controlled with adjustment screws located on the outside of the
microscope body.
The light from the illuminator, passing through the dark field condenser, is converted into a cone-shaped beam and directed at
the observed specimen. Almost all of the light passes through the lens and forms an image only by the light scattered by the
structure of the specimen. Therefore, in the field of view of the eyepiece, the bright contrast areas of the specimen structure
are displayed on a dark background.
Assembly and using
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Install a dark field condenser instead of the standard condenser of your microscope.
•
Install the desired eyepiece and choose the objective with the lowest magnification.
•
Put a drop of oil on the condenser lens; fix the microscope slide on the stage. Note: It is recommended to use a coverslip
with a thickness of 0.8—1.2mm.
•
Raise the dark field condenser until the immersion oil meets the stage and then focus.
•
If you see an off-center light spot, use the adjustment screws to bring it to the center of the field of view.
•
Note: The aperture of the objective lens used must be smaller than the aperture of the condenser.
Halogen bulb replacement
Unplug the microscope from a power source. Loosen the knurled screw on the underside of the microscope and open the panel
to gain access to the lamp. Make sure the lamp has cooled down and then remove it. Do not touch the new lamp with your
fingers; fingerprints or dirt will reduce the brightness and the lamp's life. Use gloves to replace the lamp. If necessary, wipe the
lamp with a clean, soft cloth. Use a lamp of a suitable type. Insert the contacts into the slot vertically. Then, close the panel
and tighten the knurled screw finger tight.
Fuse replacement
Unplug the microscope from a power source. Open the fuse holder located on the back of the microscope body with a flat head
screwdriver. Remove the old fuse and install a new one. Only use the appropriate types of fuses. Close the fuse holder.
Digital camera
Levenhuk MED D25T comes with a digital camera (fig. 2a), Levenhuk MED D25T LCD comes with a digital camera with an LCD
screen (fig. 2b). A digital camera is installed to the third eyepiece tube and enables observing specimens on the screen in
exquisite detail and true color, taking photos and videos, and saving the images for future reference.
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