
3B SCIENTIFIC® PHYSICS 
Laboratory Microscope BS-200  1005455 
Instruction Manual 
08/13 ALF 
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 laboratory microscope BS-200 allows twodimensional viewing of objects (thin sections of 
plant or animal specimen) in 40x to 1000x magnification. 
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 at 30° angle, rotatable through 
360°, viewing distance adjustable between 50 
and 76 mm, ±5 dioptric compensation for both 
eyepieces 
Eyepiece: Pair of eyepieces PL10x 18 mm with 
infinite optics and “high eye point” 
Objectives: Inverted objective revolver with 
plan achromatic infinite objectives 4x, 10x, 40xS 
und 100xS Oil 
Magnification: 40x, 100x, 400x, 1000x  
Object stage: x-y c ross tab le, 150 x 140 mm
with object guide and coaxial adjustment knobs 
perpendicular to the object stage, adjustment 
range 50 x 76 mm
Illumination: Adjustable 6 V, 20 W halogen 
lamp, built-in transformer for 90 to 240 V mains 
voltage 
Condenser: Condenser NA1.25, iris diaphragm,  
focussed via rack and pinion drive 
Dimensions: 320 x 200 x 400 mm³ approx.  
Weight: 6.7 kg approx. 
1 Eyepiece  
2 Tube 
3 Revolver with objectives 
4 Object guide 
5 Object stage 
6 Condenser control (not visible) 
7 Condensor with iris diaphragm 
8 Lamp housing 
9 Illumination control (not visible) 
10 Base 
11 Lamp compartment 
12 Mains switch 
13 Coarse and fine movement con-
trols with holding brake 
14 Condensor lock screw 
15 Coaxial movement control for the 
specimen stage 
16 Stand 
17 Lock screw for object stage 
18 Head lock screw 
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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. 
•  Insert the condenser. First raise the object 
stage to its highest position, insert the condenser into its holder and secure it in place 
with the fixing screw. 
•  Put the head onto the top of the stand and 
tighten the head-lock-screw. Insert the eyepieces into the tube. 
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 and clamp it to the 
object guide. 
•  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. 
•  To obtain a high contrast, adjust the back-
ground illumination by means of the iris diaphragm and the variable illumination control. 
•  Adjust the interpupillary distance so that one 
circle of light can be seen. 
•  Make the necessary eyepiece dioptre ad-
justments to suit your eyes. 
•  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. When 100x 
(oil) objective is chosen, objective oil must be 
dripped onto the slide. 
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. 
•  When using colour filters, place them di-
rectly on the lamp housing. 
•  Use the knobs of the mechanical stage to 
move the slide side-, back- and forwards. 
The vernier provides acc urate loc ation of the  
specimen area. 
•  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 Changing the lamp and fuse 
4.2.1 Changing the lamp 
•  Turn off the power switch, unplug the mains 
plug and let the lamp cool down to avoid being burnt. 
•  Pull the lamp socket out of the lamp com-
partment. 
•  In order to change the halogen lamp, use a 
cloth or something similar. Do not touch the 
lamp with your fingers. 
•  Lift out the halogen lamp and replace it with 
a new one. 
•  Close the lamp compartment again. 
4.2.2 Changing the fuse 
•  Turn off the power switch and unplug the 
mains plug. 
•  Unscrew the fuse holder on the back of the 
stand base with a screwdriver. 
•  Replace the fuse and reinsert the holder in 
its socket. 
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5. Storage, cleaning and disposal 
•  Keep the microscope in a clean, dry and 
dust free place. 
•  When not in use always cover the micro-
scope with the dust cover. 
•  Do not expose it to temperatures below 0°C 
and above 40°C and a max. relative humidity of over 85%. 
•  Always unplug the mains plug before clean-
ing or maintenance. 
•  Do not clean the unit with volatile solvents or 
abrasive cleaners. 
•  Do not disassemble objective or eyepieces 
to attempt to clean them. 
•  Use a soft linen cloth and some ethanol to 
clean the microscope. 
•  Use a soft lens tissue to clean the optics. 
•  The packaging should be disposed of at 
local recycling points. 
•  Should you need to
dispose of the equipment itself, never throw 
it away in normal domestic waste. Local 
regulations for the disposal of electrical 
equipment will apply. 
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com 
Subject to technical amendments 
© Copyright 2013 3B Scientific GmbH