AmScope B270 User manual

B270
Introducon
This manual will provide informaon pertaining to the setup and operaon of the B270 biological compound microscope.
Please familiarize yourself with the necessary precauons and procedures prior to operang this instrument. Certain
features and specicaons are subject to change.
v0.9.20220624

Safety
Before using your AmScope microscope, please read the following safety precauons carefully to avoid causing damage to
your AmScope product, or injury to yourself or others.
Turn o power if the instrument exhibits unusual or dangerous behavior such as eming smoke or unusual odors. These
can be indicaons of electrical problems, in which case the instrument should be disconnected from any power source if
safe to do so. Other indicators can be a loud buzzing sound or crackling. Contact AmScope to report such behavior.
Do not use around ammable liquids or gases. Electric instruments can ignite ammable substances which could result
in an explosion or re.
Do not use in a wet environment. Electrical components of the instrument can discharge when exposed to water, poten-
ally resulng in damage to the instrument, or injury to yourself or others.
Do not dismantle. Dismantling can result in damage to the instrument, and potenal exposure to dangerous materials or
electric current.
Noces
AmScope reserves the right to change specicaons of the product at any me without noce. Connuous eorts are
made to improve performance and reliability, which can result in changes to design and compability. Please contact Am-
Scope for any concerns regarding such changes.
Proposion 65 Noce for California Residents
Cables included with the products described in this manual can expose you to chemicals including lead,
which is known by the state of California to cause cancer, birth defects or other reproducve harm. Visit
www.P65Warnings.ca.gov for more informaon.

Contents
Specicaons .......................................................................................................................................................... 4
What’s In The Box ................................................................................................................................................... 5
1. Assembly and Setup ........................................................................................................................................... 6
1.1 The Head ........................................................................................................................................................6
1.1b The Eyepieces ............................................................................................................................................................. 7
1.1c Dioptric Adjustment ................................................................................................................................................... 7
1.1d Interpupillary Adjustment .......................................................................................................................................... 8
1.2 Objecve Lenses .............................................................................................................................................9
1.3 Light Condenser ............................................................................................................................................ 10
1.4 Specimen Stage ............................................................................................................................................ 11
1.5 Power ........................................................................................................................................................... 12
1.6 Security Leash ............................................................................................................................................... 12
2. Operaon ......................................................................................................................................................... 13
2.1 Mounng a Specimen...................................................................................................................................13
2.2 Illuminaon .................................................................................................................................................. 14
2.3 Using the Condenser .................................................................................................................................... 15
2.3a Condenser Height ..................................................................................................................................................... 15
2.3b Adjusng the Aperture ............................................................................................................................................. 16
2.3c Centering the Condenser.......................................................................................................................................... 17
2.3d Color Filters .............................................................................................................................................................. 18
2.4: Locang the Specimen, and Focusing 19
2.5 Immersion Oil ............................................................................................................................................... 20

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B270 Specicaons
Opcal System Finite conjugate
Mechanical Tube Length 160mm
Head Binocular, 30° incline, 360° rotaon
Interpupillary Adjustment Siedentopf, 48-75mm
Ocular Diameter 23.2mm
Objecve Lenses DIN standard
Objecve Parfocal Distance 45mm
Objecve Mounng Thread RMS 20.32mm
Objecve Turret Forward orientaon quadruple
Focusing System Coaxial coarse and ne focus, upper limit-stop
Fine Focusing Precision 0.002mm
Stage Design Double-layer with caliper
Stage Vercal Stroke 25mm
Stage Dimensions 118mm x 127mm
X-Y Translaon Range 70mm x 21mm
Transmied Illuminaon Variable-intensity 1W LED
Light Condenser NA1.25 Abbe condenser with iris diaphragm
Sub-stage Condenser-holder Rack and pinion, centerable
Power 100-240VAC 50/60Hz
What’s In The Box
The B270 standard ouit includes:
• One microscope
• Four objecve lenses: 4X, 10X, 40X, 100X
• One pair 10X eyepieces
• One blue color lter
• One dust cover
• One AC power cord
• 25 pipees
• 50 blank slides with 100 cover slips
• One security leash with key
Addional items may be included depending on the model.

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1. Assembly and Setup
1.1 The Head
The head can be swiveled 360° by loosening a thumb-screw on the le side of the body just below the head. Be careful
not to loosen the screw too much, as the head can become detached. Should the head become detached, simply loosen
the thumb-screw enough to allow the head to be re-seated unl ush with the body, then ghten the thumb-screw.
CAUTION: Never li the microscope by the head. If the head is not properly seated, it can become separated, causing
the body to fall, or otherwise damage the coupling mechanism. During transport, hold the microscope by the body in an
upright posion to prevent the head, eyepieces, or other parts from falling.

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1.1b The Eyepieces
This microscope uses 23.2mm eyepieces which can be easily mounted to or unmounted from the ocular tubes on the
front of the head. During transportaon, the eyepieces should not be mounted to the head to avoid falling. Dust caps
should be inserted into the ocular tubes, or alternavely an an-stac cover can be placed over the head to prevent
dust contaminaon. To use this instrument for standard observaon, eyepieces must be aached to produce a viewable
image.
Insert a pair of eyepieces into the ocular tubes. Ensure that the eyepieces have matching magnicaon, as some models
contain mulple pairs of eyepieces with dierent magnicaons. Once aached, adjust the diopter ring on the le ocular
tube unl it is neutrally aligned (no dioptric adjustment).
1.1c Dioptric Adjustment
The dioptric adjuster can be used if your eyes do not focus the same. This process requires a specimen to be in place
with the illuminator acve. Begin the process by seng the dioptric adjuster on the le ocular tube to a neutral posion.
Next, use the focus knobs to bring the image to sharp focus for your right eye. Once the right eye aains sharp focus,
rotate the dioptric adjuster unl the le eye achieves sharp focus.

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1.1d Interpupillary Adjustment
The head uses a Siedentopf adjustment mechanism which allows the ocular tubes to be moved inward or outward by
liing or lowering both halves of the housing in an arcing moon. This is referred to as interpupillary adjustment, which
is designed to properly align the eyepieces with your eyes. The adjustment is meant to match the distance between your
eyes’ pupils which is called the interpupillary distance. The adjustment process should be performed prior to observaon
of a specimen, and requires that the illuminator is acve. Aempt to look through both eyepieces, adjusng the interpu-
pillary-adjustment mechanism accordingly unl the eyepieces are aligned with your eyes, and an image can be seen with
both eyes. This process should be repeated whenever viewing a specimen to ensure alignment.

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1.2 Objecve Lenses
The microscope is equipped with four objecve lenses which are mounted to a rotang turret between the head and the
specimen stage. Should the lenses be removed for transport, they are mounted and unmounted by rotang each lens
clockwise or counter-clockwise respecvely. The lenses are typically mounted in order from 4X to 100X, but can be inter-
changed as desired. This microscope is compable with DIN-standard objecve lenses, which allows aermarket lenses
to be used as needed. These lenses must comply with the following DIN* specicaons:
• 20.32mm RMS mounng thread
• 160mm mechanical tube-length
• 45mm parfocal distance
*DIN stands for Deutsches Instut für Normung which is a German standards organizaon. Microscopes and objecve
lenses which are DIN compliant will use the aforemenoned specicaons.

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1.3 Light Condenser
This microscope uses a light condenser to focus and control the amount of light which passes through the specimen. An
Abbe condenser is pre-mounted so no inial setup is required. Addional condensers may be used such as darkeld con-
densers. This model uses a boom-loading design, so the condenser is mounted from under the holder, sliding upward
into posion.
In order to remove the Abbe condenser and aach a dierent condenser, the illuminator’s eld lens must rst be re-
moved. Begin by raising the stage using a coarse focus knob to provide more space under the stage. Use the condens-
er-holder’s height adjuster to raise the holder to its maximum height. Unscrew the illuminator’s eld lens by rotang
it counter-clockwise unl it can be removed. Once removed, locate the condenser’s locking screw on the front of the
holder. Use one hand to hold the condenser in place to avoid dropping it, then turn the screw counter-clockwise unl
the condenser is released. Once the condenser has been removed, insert the desired condenser into the holder unl it is
fully seated, then ghten the locking screw. Once the condenser is secured, replace the illuminator’s eld lens.

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1.4 Specimen Stage
The stage has an adjustable height limit. This is used to prevent the stage from being raised too high which could result in
damaging the specimen or even the objecve lenses. The adjustment screw is located on the body just behind the stage.
Rotate the objecve turret unl the 100X objecve lens is in place. With a specimen mounted on the stage, slowly raise
the stage using the coarse-focus knob unl the specimen is a few millimeters from the lens. Use the ne-focus knob to
connue raising the stage unl the specimen barely comes in contact with the lens. The 100X lens has a spring-loaded
nose. If the nose begins to compress, the stage is too high. When the specimen is able to make contact with the lens
without compressing the nose, this is the appropriate maximum height. The height-adjustment screw should be ght-
ened to set the stopping posion. If the specimen was too far from the lens, and could not make contact, loosen the
adjustment screw slightly, then connue to make ne focus adjustments unl the specimen is high enough. Once the
height is properly set, ghten the adjustment screw.

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1.5 Power
Before connecng the microscope to a power source, the power switch should be set to the “O” (o) posion. Do not
use the instrument near ammable materials, nor in wet environments. Aach the provided power cable, ensuring that
the cable is fully inserted with a rm connecon. Plug the cable into an AC outlet, then set the power switch to the “–”
(on) posion to acvate the built-in illuminaon.
1.6 Security Leash
A security leash can be used with the B270 as a the deterrent. The leash should be secured to an immobile object by
guiding the leash around or through the object, then through the leash’s loop. Once the leash is secure, the lock poron
of the leash can be aached to the microscope. The microscope’s security slot is located on the rear power panel be-
tween the power switch and power port. With the lock in its unlocked posion, insert the tab into the security slot. Set
the lock to its locked posion using key or combinaon pad.
This security system is designed to be a deterrent against opportunisc the. Extreme force can cause the security slot to
warp or break which can result in damage to the microscope’s electrical system.

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2. Operation
2.1 Mounng a Specimen
This microscope is designed to view translucent specimens mounted primarily on 3” x 1” glass slides. A metal template
with caliper is aached to the top of the stage. A prepared slide can be placed on the stage by pushing the caliper lever
outward to open the caliper, then sliding the slide in place so the long edge is ush against the back edge of the tem-
plate. Gently releasing the caliper will secure the slide in place.

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2.2 Illuminaon
[image: brightness wheel]
The microscope’s power switch is located on the rear of the body. Turn on the microscope’s illuminaon by pressing the
power switch to the “–” (on) posion. As magnicaon increases, more light will be necessary to view the specimen. Use
the wheel on the right side of the microscope’s base to adjust the illuminator’s brightness as needed. Avoid using the
microscope for long duraons with excessive brightness, as this can strain the eyes.

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2.3 Using the Condenser
The condenser focuses light from the microscope’s lamp onto the specimen in order to maximize brightness and resolu-
on. There are mulple adjustments which can be made to suit dierent applicaons.
2.3a Condenser Height
[image: adjusng condenser height]
The condenser should be raised to its maximum height to achieve opmal brightness and resoluon. The height-adjust-
ment knob is located on the le side of the microscope, just behind the condenser holder. Rotate the knob clockwise to
lower the condenser, and counter-clockwise to raise the condenser. Lowering the condenser is typically done to perform
a funcon such as applying immersion oil. The height of the condenser also aects its numerical aperture. Lowering the
condenser will decrease the eecve aperture, therefore increasing the observed depth of eld in a manner similar to
using the iris diaphragm. This can negavely impact image quality due to diracon, so it is recommended to use the
condenser at its maximum height.

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2.3b Adjusng the Aperture
[image: aperture lever]
The condenser has a built-in iris diaphragm which creates an internal aperture. This aperture controls the amount of light
which passes through the condenser, and parally collimates the light. Decreasing the size of the aperture restricts the
amount of light used which in turn reduces the amount of scaered light. The notable eects are a reducon in bright-
ness as well as increased depth of focus. Decreasing the aperture too much will result in diracon arfacts which dete-
riorate image quality. As objecve magnicaon increases, more light will be requires to accommodate higher numerical
apertures. The aperture should be increased accordingly.

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2.3c Centering the Condenser
The condenser can also be centered to improve alignment with the set objecve lens. Two recessed centering screws are
located on the front of the condenser-holder -- one on either side of the locking screw. Adjustment requires a 2.5mm hex
wrench. Rotang either screw clockwise will increase tension and push the condenser diagonally. Because the micro-
scope’s viewing head produces an inverted image, the condenser will appear to move in a direcon opposite the me-
chanical movement.
To center the Abbe condenser, its iris diaphragm must be used as reference. This is ideally done using a telescoping
eyepiece which can be adjusted to focus on the condenser’s iris. Otherwise, an eyepiece can be removed from the
viewing head, allowing you to view an image of the iris inside the ocular tube. The illuminator must be acve to provide
the necessary light, but the brightness should be adjusted to a low level since you will be looking directly at the light.
With the condenser raised to its maximum height, you should see an image of the iris. Use the condenser’s adjustment
lever to increase or decrease the size of the aperture unl it is slightly smaller than the eld of view. Tightening the right
screw will move the image of the iris downward and to the right. Tightening the le screw will move the image of the iris
downward and to the le. Loosening either screw will move the image of the iris in an opposite direcon. Make gradual
adjustments to both screws unl the iris appears centered in the eld of view. You can increase or decrease the aperture
as needed to gauge the alignment.

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2.3d Color Filters
[image: lter holder with lter]
32mm lters can be used with this microscope to alter the color of light. Common lters include green, yellow, and blue.
A green lter is commonly used to concentrate light in the middle of the spectrum, as most opcs are designed to pro-
duce opmal results using these center wavelengths. Blue lters can be used to compensate for light sources with warm-
er color, or to beer image certain specimens. Yellow lters can be used with cooler light sources like LED to decrease
higher-intensity wavelengths which can fague the eyes over long periods.
The condenser is equipped with a lter-holder located on its boom. The holder has a small peg which can be pulled in
a clockwise moon to swing the holder outward. The condenser may need to be rotated to allow the space needed to
open the holder. Once the holder has been fully opened, a 32mm lter can be placed within the holder’s recess. Close
the holder to engage the lter.

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2.4: Locang the Specimen, and Focusing
With the specimen mounted on the stage, and the illuminator turned on, use the stage’s X-Y control knobs under the
right side of the stage to adjust the posion of the specimen. The larger knob will move the specimen forward and
backward, while the smaller knob will move the specimen le and right. Compound microscopes produce inverted
images due to the nature of the opcal system. Sliding the specimen towards the front of the microscope will result in
the viewed image moving in the opposite direcon. Use the knobs unl the specimen appears to be centered under the
objecve lens. This will be the starng point.
Observaon should typically begin at the lowest magnicaon. This provides the broadest view of the specimen. Rotate
the objecve turret to set the lowest magnicaon lens in place. The condenser is typically designed with a range of
aperture values ranging from approximately 0.10 to 1.25. If using a 4X objecve lens with a 0.10 aperture, adjust the con-
denser’s aperture using the lever on the outside of the condenser to reduce the size of the aperture. This will maximize
the focus depth. When higher magnicaons are used, the aperture should be adjusted more open to beer match the
objecve lens’ aperture.
Look through the eyepieces, adjusng the interpupillary adjusters as needed to achieve proper alignment. Both eyes
should see the same image with a bright, round background. If the image appears oset or obscured, you should conn-
ue to adjust the interpupillary distance unl the image appears correct. The le ocular tube also has a dioptric adjuster
which can be used if the eyes do not focus the same. If the eyepieces are properly aligned, but the light-source appears
oset, use the two centering screws aached to the condenser holder to adjust the condenser’s posion unl it is cen-
tered. For trinocular models, the photo tube can be adjusted to parfocal by rst obtaining focus with the right eye, then
adjusng the length of photo tube by unscrewing the top poron of the tube from the boom poron unl the camera
obtains focus, then ghtening the locking ring in the middle unl it engages against the boom poron of the photo
tube.
[image: adjusng the coarse/ne focus]
The stage should be set to a low posion when mounng the specimen. Gradually raise the stage using the coarse-focus
knob. If you have already performed the height-limit adjustment, the specimen should come into focus near the maxi-
mum height. Once you begin to see shapes through the eyepieces, use the ne-focus knobs to adjust the focus unl you
can see details with clarity. Use the X-Y control knobs to reposion the specimen unl the area of interest is in view. You
can increase magnicaon as needed by rotang the objecve turret. When doing so, it is advisable to watch the lens as
it is set in place to ensure it will not collide with the specimen. Slight adjustments to focus should be made at each mag-
nicaon, as well as to the condenser’s aperture and the illuminator’s brightness.

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2.5 Immersion Oil
Certain high-magnicaon objecve lenses with numerical-apertures over 1.0 will be marked with the word “oil.” This
signies that the lens is designed to work with specialized oil as an immersion medium. The immersion oil is used be-
tween lenses and specimens to eliminate air from the opcal path in order to maintain high resoluon. This oil is only
intended to be used with compable lenses, and should not be used with non-oil lenses. The most-common lens to use
oil is a 100X objecve lens with a numerical aperture of 1.25 or higher. A small drop of oil is placed on the specimen,
then the lens would be rotated into place. The specimen must be appropriately prepared to allow the use of oil, such as
by using a cover slip. When the stage is raised to achieve focus, the objecve lens will make contact with the oil.
Immersion oil should also be used with oil-compable condensers. Condensers with numerical apertures over 1.0 must
use an immersion medium to achieve the high numerical apertures. A drop of immersion oil would be placed on the con-
denser’s top lens, then the condenser would be raised so the oil makes contact with the underside of the specimen. This
technique should only be used with specimens which have been properly prepared, such as being mounted on a glass
slide.