3B Scientific Binocular Polarization Microscope User Manual

3B SCIENTIFIC® PHYSICS
Binocular Polarisation Microscope 1012404
08/13 ALF
1 Eyepiece 2 Tube 3 Analyser 4 Revolver with objectives 5 Specimen clips 6 Object stage 7 Condenser control 8 Condensor with iris diaphragm,
filter holder and polariser 9 Lamp housing 10 Illumination control 11 Mains switch 12 Lock screw for polariser 13 Coarse and fine movement
controls with holding brake 14 Lock screw for object stage 15 Stand 16 Head lock screw
1. Safety notes
For power supply use only electrical sockets
with ground contact.
Caution! The Stirling engine becomes hot during use. Risk of burns!
Do not touch the lamp during or immediately
after use.
2. Description, technical data
The binocular polarisation microscope allows two-dimensional viewing of objects (thin sec­tions of rock, plant or animal specimen) in 40x to 400x magnification in polarised light.
Stand: Robust, all metal stand with arm perma­nently connected to the base. Focussing by means of separate knobs for coarse and fine adjustment located on either side of the stand and operated by rack and pinion drive with ball
bearings and retaining lever, adjustable stopper for protecting the object slides and objective.
Tube: Binocular head, 30° viewing angle, 360° rotatable head, viewing distance adjustable be­tween 54 and 75 mm, ±5 dioptric compensation for both eyepieces
Polarisation equipment: Polariser with scale and analyser, which can be inserted into the tube
Eyepiece: Pair of wide field eyepieces WF 10x 18 mm
Objectives: Inverted objective revolver with 3 achromatic objectives 4x / 0.10, 10x / 0.25, 40x /
0.65
Magnification: 40x, 100x, 400x Object stage: Circular object stage 120 mm in
diameter, which can be rotated 360°, scale with Vernier and 2 specimen clips
Illumination: Adjustable 6 V, 20 W halogen lamp incorporated into the base, universal 85 to 265 V, 50/60 Hz power supply
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Condenser: Abbe condenser N.A.1.25 NA 0.65 with iris diaphragm , filter holder and blue filter, focussed via rack and pinion drive
Dimensions: 240 x 190 x 425 mm³ approx. Weight: 6 kg approx.
3. Unpacking and assembly
The microscope is packed in a molded styro­foam container.
Take the container out of the carton remove
the tape and carefully lift the top half off the container. Be careful not to let the optical items (objectives and eyepieces) drop down.
To avoid condensation on the optical com-
ponents, leave the microscope in the original packing to allow it to adjust to room tem­perature.
Using both hands (one around the pillar and
one around the base), lift the microscope from the container and put it on a stable desk.
The objectives will be found within individual
protective vials. Install the objectives into the microscope nosepiece from the lowest magnification to the highest, in a clockwise direction from the rear.
Put the head onto the top of the stand and
tighten the head-lock-screw. Insert the eye­pieces into the tube.
Insert the analyser into the slot on the re-
volving nosepiece.
Insert the condensor with polariser and tigh-
ten the lock-screw.
4. Operation
4.1 General information
Set the microscope on a level table.
Place the object to be observed in the centre
of the specimen stage. Use the clips to fas­ten it into place.
Connect the mains cable to the net and turn
on the switch to get the object illuminated.
Make certain that the specimen is centered
over the opening in the stage.
Adjust the interpupillary distance so that one
circle of light can be seen.
Make the necessary eyepiece dioptre ad-
justments to suit your eyes.
To obtain a high contrast, adjust the back-
ground illumination by means of the iris dia­phragm and the variable illumination control.
Rotate the nosepiece until the objective with
the lowest magnification is pointed at the
specimen. There is a definite “click” when each objective is lined up properly.
NOTE: It is best to begin with the lowest power objective. This is important to reveal general structural details with the largest field of view first. Than you may increase the magnification as needed to reveal small details.
To determine the magnification at which you are viewing a specimen, multiply the power of the eyepiece by the power of the objective.
Adjust the holding brake to give a suitable
degree of tightness in the focusing mecha­nism.
Adjust the coarse-focusing-knob which
moves the stage up until the specimen is fo­cused. Be careful that the objective does not make contact with the slide at any time. This may cause damage to the objective and/or crack your slide.
Adjust the fine-focusing-knob to get the im-
age more sharp and more clear.
Colour filters may be inserted into the filter
holder for definition of specimen parts. Swing the filter holder out and insert colour filters.
Always turn off the light immediately after
use.
Be careful not to spill any liquids on the mi-
croscope.
Do not mishandle or impose unnecessary
force on the microscope.
Do not wipe the optics with your hands.
Do not attempt to service the microscope
yourself.
4.2 Using the polarisation equipment
Insert the analyser into the slot on the re-
volving nosepiece.
Rotate the polariser until the planes of the
polariser and the analyser are exa ctly crossed, so that one sees a black background.
Any object with a doubly-refracting (birefringent) structure should now appear brightly illuminated against the dark background. If that does not occur, it is possible that the direction of light vibration of the object coincides with the polari­sation direction. Whether or not that is the case can be tested by rotating the polariser or the specimen itself.
A birefringent object, when rotated continuously, shows up brightly after each 90° rotation and is dark between these positions. In contrast, ob­jects that are isotropic and not birefringent re­main dark in all positions.
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