Bresser 40-640x Mode D'emploi page 13

Now, turn on the light using the switch on the microscope base. You'll find
further tips about the light source in the next section. Now, place a pre-
pared slide under the clips on the stage (4), directly under the objective
(1). When you take a look through the eyepiece, you can see the magni-
fied specimen. At this point, you still might see a slightly fuzzy picture.
Adjust the image sharpness by slowly turning the focus knob (2). You
can now select a higher magnification by turning the objective turret and
selecting a different objective.
When you do so, note that the sharpness of the picture must be adjusted
again for the higher magnification. Also, the higher the magnification,
the more light you will need for good illumination of the picture. The
wheel with pinhole apertures (9) below the microscope stage (4) will
help you in viewing very bright or clear-sighted preparations. Turn the
wheel (9) till the best contrast is achieved.
4. Observation (electronic light source)
For observation with the electronic light source (6) you need to insert
2 AA batteries 1.5 V, in the battery compartment (8) on the base of the
microscope (7). The battery compartment is opened using a Phillips
screwdriver. Insert the batteries with the correct polarity (+/- indication).
ut the batter cover first into the small opening so that the lid fits per-
fectly. Now you can tighten the screw. The lighting is switched on when
you turn the switch on the microscope base.
Now you can observe in the same way as described in the previous
section.
TIP: The higher the magnification you use the more light is required for
a good illumination of the picture. Therefore, always start your experi-
ments with a low magnification.
5. Condition and prepare viewed objects
5.1. Condition
This microscope features transmitted light, so that transparent speci-
mens can be examined. If opaque specimens are being examined, the
light from below goes through the specimen, lens and eyepiece to the eye
and is magnified en route direct light principle . Some small water organ-
isms, plant parts and animal components are transparent by nature, but
many others require pretreatment — that is, you need to make a thinnest
possible slice of the object by hand cutting or using a microtome, and
then examine this sample.
5.2. Creation of thin preparation cuts
Specimens should be sliced as thin as possible. little wax or paraffin is
needed to achieve the best results. Put the wax into a heat-safe bowl and
heat it over a ame until the wax is melted. ou can use a candle ame
to melt the wax.
GB
13