BestScope BS-2020B User manual

Biological Microscope
Model：BS-2020B/T
Instruction Manual
This manual is written for biological microscope BS-2020B/T. To ensure the safety, obtain
optimum performance and to familiarize you fully with the use of this microscope, it is
recommended strongly that you study this manual thoroughly before using the microscope and
retain this manual in an easily accessible place near the work desk for future reference.

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CONTENTS BS-2020
User Notices………………………………………………………… 2
1 Components Name…………………………………………………… 4
2 Installation …………………………………………………………… 5
2.1 Installing Diagram…………………………………………………………… 5
2.2 Installing Steps ……………………………………………………………… 6
3 Adjustment & Operation ………………………………………… 10
3.1Adjustment Controls …………………………………………………………… 10
3.2 Operation ………………………………………………………………………… 11
4 Technical Specifications …………………………………………… 14
5. Outfit Table ………………………………………………………… 15
6 Troubleshooting ……………………………………………………16

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User Notices BS-2020
I．Safety note
1. Carefully open the box, avoid the accessories, like lens, dropping to ground and being damaged.
2. Do keep the instrument out of direct sunlight, high temperature or humidity, dusty and easy
shaking environment. Make sure the stage is smooth, horizontal and firm enough.
3. When moving the instrument, please use two hands to grip with the two sides of the microscope
body.
4. When running, the lamp house and nearby parts will be very hot. Please ensure there is enough
cooling room for them.
5. Make sure the instrument is earthed, to avoid lighting strike.
6. For safety, be sure the main switch is in “O”(off) state before replacing the halogen (LED) lamp or
the fuse, then cut off the power, and do the operation after the lamp bulb and the lamp house
completely cool.( specified lamp: Halogen Lamp 6V/20W or LED lamp 3W)
7. Check the input voltage: be sure the input voltage which signed in the back of the microscope is
consistent with the power supply voltage, or it will bring a serious damage to the instrument. Use
the factory supplied power cord, please.
II．Maintenance
1. All the lenses have been well checked and adjusted. It is forbidden to disassemble them yourself.
2. The nosepiece and coarse/fine focus unit have a compact and precise frame, please don’t
disassemble them as possible as you can.
3. Keep the instrument clean, wipe dust regularly, and be attention to avoid contaminating the
optical elements especially.
4. The contaminations on the prism, as finger mark and oil, could be gently wiped with a piece of soft
cloth or tissue paper, gauze which has been immersed in pure alcohol or xylene. (note that the
alcohol and the xylene are all burned easily, do not let them near the fire, and use them in a
drafty room as possible as you can.)
5. Don’t use organic solvent to wipe the non-optical elements, when you need to clean, use the soft
detergent, please.
6. When using, if the microscope is splash by liquid, cut off the power at once, and wipe up the
moisture.
7. Do not disassemble any parts of the microscope. That will affect the function or decline the
performance of the microscope.
8. Place the instrument in a cool, dry position. After using the microscope, remember to cover it
with dust helmet. Do wait for the lamp house cooling completely before cover.

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1. Name of Components BS-2020
Biological Microscope BS-2020B
Eyepiece
Binocular/Trinocular viewing head
双目观察头
Nosepiece
Objective
Body
Condenser
Collector

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2．Installation BS-2020
2.1 Installing Diagram
The following figure shows the installation sequence of the components. The number in the figure
shows the assembly steps.
Before installing, be sure every components is clean, do not score any parts or glass surface.
Keep well with hexagon wrench provided. When replacing the components, you will need it
again.
显微镜体
物镜
Binocular
看
Viewing
Head
头
10X 目
镜
④
③
①
②
电源线
Binocular Viewing Head
10X Eyepiece
Objective
Body
Cable Wire

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BS-2020
2.2 Installing Setps
①
Fig.1
Fig.3
Fig.2
2.2.1 Install the binocular viewing head
(Fig.1-2)
Insert the binocular viewing head into the head of
the body, turn to the right position, then fix up it with
bolt①.
2.2.2 Install the eyepiece (Fig.3-4)
Insert the eyepieces into the eyepiece tube until
they are against each other.
Fig.4 shows the status after the installation.
Note:
Working Environment Requirement：
1．Ambient temperature: 5°C to 40°C
. (41°F to 104°F)，Maximum R.H：85%。
2．High Temperature will result in a mildewing,
dew and even ruinous instrument.
3．Avoid placing the instrument in a dusty
environment. When ending your microscope
operation, please cover it with the dust cover.
4．Lay the microscope in a plan and stable
position please.
Fig.4

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BS-2020
②
①
Fig.6
Fig.5
2.2.3 Installing the Objective (Fig.5-6)
1. Adjusting the coarse focus knob until the
support device of the mechanical stage
reaches its low limit position.
2. Screw the lowest magnification objective
into the nosepiece from the left or the right
side, then revolve the nosepiece clockwise
and mount other objectives in sequence of
magnification.
Installing objective this way will make the
change of magnification easier during
using.
Clean the objectives regularly, for lens is
susceptible to dust.
When operating, use 10×magnification
objective to search and focus specimen
firstly, then replace with higher
magnification objective if necessary.
When replacing the objective, slowly turn
the nosepiece until you hear “clicked”,
which means the objective is in the
required position—center of the light
path.
2.2.4 Install the color filter (Fig.7)
1. Rotate the condenser holder①out as Fig.7
shows.
2. Put the filter②into the condenser holder,
and then switch back the holder.
Baby blue and green filters are available in
standard outfit.
Fig.7

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BS-2020
③②
⑥
④⑤
2.2.5 Connecting the Power Cord
(Fig.8-10)
★The cable and cords are vulnerable
when bent or twisted, never subject the
power cord to excessive force.
1. Before connecting the power cord, switch
the main switch①to “O”(off).
2. Plug the power cord②into the socket③on
microscope safely. Make sure the connection
is well。
3. Plug the power cord④into the power source
socket safely. Make sure the connection is
well。
★Do use the supplied power cord all the
time. If lost or damaged, select the same
standard cord please.
★Either 110V or 220V can be selected as the
input voltage of this microscope. (The input
voltage has been preset in the microscope
before leaving factory.
2.2.6 Replacing the fuse (Fig.7, 9, 10)
Do remember to turn the main switch①
off before replacing the fuse, and unplug the
power cord②. Dig the fuse⑤kits out of the
power source socket③with your fingers,
replace with a new fuse, then insert it back
to the power source socket again.
★250V500mA fuse for 220V.
★250V1Afuse for 110V.
Fig.8
①
Fig.9
Fig.10

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BS-2020
②
①
④
.
⑥
⑤
2.2.8 Installing and replacing the lamp (Fig.11,
12, 13)
0.246810There are two types of lamp for illumination,
halogen Lamp 6V/20W and LED lamp 3W.
When changing halogen lamp：
1. When being used, or soon after it is turned off, the
lamp, the lamp house and nearby parts will be very hot
and will cause serious burns. Please turn the main
switch on “O” (off), pull up power plug, and make sure
the bulb, the lamp house and periphery are all cool.
Then, you can do your replacing.
2. Loosen the bolt①on the lamp holder window at the
base of the microscope by screwdriver, screw lamp
holder window②out.
3. Pull out the halogen bulb③, hold the bulb after you
wrap it with gauze or other protection materials, then
depress the plugs into the jack on the lamp house.
4. Finally, cover the lamp holder window, screw down the
bolt①.
Please insert the lamp gently, or it will be damaged by
excessive extrusion.
Do not touch the Halogen bulb with your hands. It
will shorten the service life or cause it to burst. If you
leave fingerprints on the surface carelessly, clean it
with a dry soft cloth.
When changing LED lamp：
1. The working life of LED lamp is very long, so it is hard
to be damaged, if the bulb is unfortunately damaged,
please purchase a new one from supplier.
2. Removing the bottom board ⑥on the base of
microscope by screwdriver, after removing the bolt⑤,
LED bulb can be taken down, replaced with a new one,
the new bulb should be fixed on holder with bolt⑤.
3. Fixing the bottom board to the base of microscope with
the original bolt.
Please take down the bottom board slowly when
removing it, or the inside electrical wire may be
damaged.
Fig.11
③
Fig.13
Fig.12

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3. Adjustment & Operation BS-2020
3.1Adjustment Set Diagram (Fig.14-15)
Fig.14
Fig.15

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BS-2020
3.2 Operation
③
②
①
Spanner
3.2.1Adjusting the brightness (Fig.16)
1. Connect the power, turn on the main switch ①
(figure 16) to “-”(on).
2. Turning the brightness adjustment knob②
anti-clockwise, the voltage raise, and the brightness
strengthen; turning it clockwise, the voltage decline,
and the brightness weaken.
Using the lamp in a low voltage condition will
prolong the use life.
3.3.2 Placing Specimen (Fig.17)
1. Place the slide③on the mechanical stage. Use the
slide holder to clamp the slide gently.
2. Turn the portrait and lateral adjustment knob of the
mechanical ruler④, move the specimen onto the
required position.
Be careful when changing the objective. If you
finish the observation with the short working
distance objective, and want to change another
one, be careful of not letting the objective touch
the specimen.
3.3.3 Focusing (Fig.18-19)
1. Use the 10×objective to make focus, to avoid the
objective touch with the specimen, you should
raise the mechanical stage at first, let the specimen
close to the objective, then slowly separating them
to focus.
2. The operator can conversely turn the coarse focus
knob①to get the specimen down, and search
images in the 10×ocular simultaneously, then use
the fine knob②to focus. At this moment, you can
replace other magnification objectives safely, and
focus without the risk of destroying the specimen.
The tightness of the tension adjustment collar has
been adjusted before leaving factory, if finding
it’s loosing (the mechanical stage drop itself
because of gravity), please use the Spanner to
turn the tension adjustment collar③until the
tightness is in order.
Fig.18
Fig.19
Fig.17
③
④
①
②
Fig.16

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BS-2020
3.3.4 Adjusting the center and height of the
condenser (Fig.20)
Rotating the focus knob of the condenser, let the
condenser move up and down, let the condenser
raise when we use high-power objective, and go
down when we use low power objective.
The center of the condenser should be coaxial
with the optical axis of objective, it has been
adjusted before leaving factory, you don’t need
to adjust it by yourself.
The high limited place of the condenser has
adjusted before leaving factory; you don’t need
to adjust it by yourself.
3.3.5 Adjusting the aperture diaphragm
(Fig.20, 21)
Rotating the Aperture diaphragm adjust
lever①, change the opening of the aperture
diaphragm.
⚫If the opening of the aperture diaphragm too
small, it will lead to low brightness and low
resolution. But the contrast and the depth of
field will increase. Reversely, if the opening of
the aperture diaphragm too large, the
brightness and the resolution will increase, but
the contrast and depth of field will decrease.
⚫Generally, we can get the good quality image
with sufficient contrast when the aperture
diaphragm opened to the 70～80% of the
objective’s numerical aperture. If the opening
of the aperture diaphragm too small, then it
will lead to low resolution. Thus, when we
observe a transparent specimen, please do not
reduce the size of the aperture smaller than
60% unless we only need very low contrast.
⚫The value of the numerical aperture is signed
on the tube of the each objective, for example,
the sign of 10/0.25 means the magnification is
10×and the numerical aperture is 0.25mm.
⚫To observe the image of the aperture
diaphragm, remove the eyepiece，observe the
image through the tube directly.
①
Fig.20

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BS-2020
3.3.6 Adjusting the interpupillary
distance (Fig.22)
The interpupillary distance range:
55mm～75mm.
When observing with both eyes, hold on
the left and right prism holder, turn around the
axis, and adjust the interpupillary distance until
the left and right fields of view coincide
completely.
3.3.7Adjusting the Diopter (Fig.23)
1. Observe the right ocular tube with your
right eye. Turn the Coarse & Fine Focus
Knob to bring the specimen into focus.
2. Observe the left ocular tube with your left
eye. If not in focus just adjust the Diopter
Ring①to make it in focus.
★ The diopter range of the eyepiece is ±5
diopter. The value aligned to the reticle
on the viewing head is the diopter in use.
Fig.22
Fig.23

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4．Technical Specifications BS-2020
(1) Main specifications
Tube Length
160mm
Viewing Head
Compensation Free Binocular Head, Inclined at 30, Interpupillary distance:
55-75mm
Eyepiece (Ocular)
Line field of view: 18mm
Nosepiece
Backward Quadruple Nosepiece
Objective
Achromatic: 4×, 10×, 40×, 100×
Focus System
Coaxial Coarse and Fine Focusing System, Sensitivity and Graduation of Fine
Focus: 0.004mm, range 24mm
Condenser
Abbe NA 1.2
Stage
Double layer mechanical stage, area: 132×142mm, movement range: 75×40mm
Lamp-House
Halogen lamp 6V20W or LED lamp 3W
(2) Eyepiece, Objectives
1. Objectives
Magnification
Numerical Value
Aperture
Diaphragm(N.A)
Cover Glass
Thickness (mm)
Focus f (mm)
Working
Distance (mm)
Working
Mode
4×
0.10
0.17
31.05
18
dry
10×
0.25
0.17
17.13
6.5
dry
40×
0.65
0.17
4.65
0.53
dry
100×
1.25
0.17
2.906
0.13
oil
2. Eyepiece
Kind
Magnification
Focus f (mm)
Linear Field Of View (mm)
Plan Eyepiece
10×
24.95
Φ18
3. Total magnification
Eyepiece
10×
10×
10×
10×
Objectives
4×
10×
40×
100×
Total Magnification
40×
100×
400×
1000×

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5．Standard Outfit Table BS-2020
Component name
Specification
Number
Standard outfit
Body
Frame
1
〇
Double layer mechanical stage
1
〇
Condenser holder
1
〇
Viewing system
Compensation Free Binocular Head
1
〇
Monocular Head
1
Optional
Condenser
Abbe NA 1.2
1
〇
Nosepiece
Quadruple Nosepiece
1
〇
Lamp-House
Halogen lamp 6V20W (or LED lamp)
1
〇
Spare lamp (halogen lamp 6V20W)
2
〇
Spare fuse 50T250V2A (or 500mA)
1
〇
Eyepiece
Plan 10×
2
〇
Objective
Achromatic 4×
1
〇
Achromatic 10×
1
〇
Achromatic 40×
1
〇
Achromatic 100×(oil, spring)
1
〇
Condenser
Bright field condenser with iris
diaphragm
1
〇
Filter
Blue, green
1 piece each
color
〇

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6．Troubleshooting BS-2020
PROBLEMS
REASON FOR PROBLEMS
SOLUTION
Ⅰ. Optical Part:
1. The edge of the
field of view has
shadow or the
brightness is
asymmetry
The nosepiece is not in the located
position (The objective is not in the
center of the light path)
Adjust it into the located position
(turning the objective to let it in the
center of the light path correctly)
The filament shadow not in center
Adjust it to center
The surface of the lens has
contaminant (condenser, objective,
eyepiece, Collector lens)
Clean the lens
2.Find dust and stain
in the field of view
The surface of the lens has
contaminant (condenser, objective,
eyepiece, Collector lens)
Clean the lens
There are stains on the slide
Clean the lens
The position of condenser is too low
Loosen the bolt of the condenser,
adjust its position and tighten it again
3.Bad image quality
(low-resolution, bad
Contrast)
No cover glass on the specimen
Add cover glass
The cover glass is too thick or too
thin
Use normal thickness cover
glass(0.17mm)
The specimen is on the reverse side
Turn it around
Oil the dry objective (especially easy
to happen on 40X)
Clean the objective
The surface of the lens has
contaminant (condenser, objective,
eyepiece, Collector lens)
Clean the lens
No oil with oil objective
Use oil
There are air bubbles in the oil
Eliminate the bubbles
Use the unspecified oil
Use the specified oil
The opening of Aperture diaphragm
is too large
turn it down to the proper size
There are stains on the incidence
lens of the binocular head
Clean the lens
The opening of Aperture diaphragm
is too small
Opening it to the proper size
The position of condenser is too low
Adjust its position

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4.The image one side is clear and
the other side is faint
The condenser is not in the center
of the field or the condenser
incline
Reset the condenser and adjust
the Central bolt of the condenser
carefully
The nosepiece is not in the
located position
Rotate the nosepiece to the
required position
The specimen is in the floating
state
Fix it firmly
5.The image move when focus it
The specimen is floating on the
stage
Fix it firmly
The nosepiece is not in the
located position
Rotate the nosepiece to the
required position
6. The image seems yellow
slightly
Not use the blue filter
use the blue filter
7. The height of the brightness is
not enough
The opening of Aperture
diaphragm is too small
Adjust it again
The position of condenser is too
low
Adjust its position
The surface of the lens has
contaminant (condenser,
objective, eyepiece, Collector
lens)
Clean the lens
II. Mechanical Part:
1. The image can’t focus
using high-power objective
The slide is on the reverse side
The cover glass is too thick
Reverse the slide
Use normal thickness cover
glass(0.17mm)
2.The objective touch the
cover glass when it change
from low power to
high-power
The slide is on the reverse side
The cover glass is too thick
Reverse the slide
use normal thickness cover
glass(0.17mm)
3.The specimen moving not
fluently
The slide holder is not fixed
effectively
Fix it firmly
4.The left and right fields of
view is not coincided.
The interpupilliary distance is not
correct
Adjust it correctly
5.The eyes are
uncomfortable
The diopter is not right
Adjust the diopter according your
sight
The brightness of illumination is
not properly
Adjust the bulb voltage
III. Electric Part:

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1. The lamp can’t light
No power supply
Check the power cord, and
connect them exactly
The installation of the bulb is
wrong
Install the bulb correctly
The bulb burn out
Change a new bulb
2. The bulb burn out
suddenly
Not use the specified lamp
The voltage is too high
Use the required lamp, if the
situation has not change after
replacing the bulb, please connect
with maintenance department
3. The height of the
brightness is not enough
Not use a appointed lamp
The voltage is too low
Use a appointed lamp
Add the voltage
4. The light glimpse
The bulb is going to spoil
Change the bulb
The bulb is not plug in the socket
correctly
Check it and plug in the socket
firmly