KERN OPO-1 User manual

OPO-1-BA-en-2111
KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
Email: [e-mail]
Tel: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
Operating instructions
Polarizing microscope
KERN OPO-1
OPO 185
Version 1.1
01/2021

OPO-1-BA-en-2111 2
EN
KERN OPO-1
Version 1.1 01/2021
Operating instructions
Polarizing microscope
Table of Contents
1Before use......................................................................................3
1.1 General notes............................................................................................................................ 3
1.2 Notes on the electrical system................................................................................................ 3
1.3 Storage ...................................................................................................................................... 4
1.4 Maintenance and cleaning....................................................................................................... 5
2Nomenclature ................................................................................6
3Technical data / Equipment..........................................................9
4Assembly .....................................................................................11
4.1 Analyzer unit (+ incident light unit) ...................................................................................... 12
4.2 Microscope head .................................................................................................................... 12
4.3 Objective ................................................................................................................................. 12
4.4 Eyepieces ................................................................................................................................ 13
4.5 Condenser (Swing-Out) / Transmitted Light Polarizer ....................................................... 13
5Operation .....................................................................................13
5.1 First steps ............................................................................................................................... 13
5.2 (Pre-) Focusing ....................................................................................................................... 14
5.3 Adjusting the interpupillary distance ................................................................................... 15
5.4 Dioptric compensation........................................................................................................... 15
5.5 Centering the microscope stage........................................................................................... 16
5.6 Setting the magnification ...................................................................................................... 18
5.7 Using the Eyecups ................................................................................................................. 19
5.8 Adjustment of the analyzer unit............................................................................................ 20
5.9 Adjustment of Köhler illumination for transmitted light .................................................... 21
5.10 Setting the illumination for incident light ............................................................................ 24
6Lamp replacement ......................................................................25
7Fuse replacement........................................................................25
8Using optional accessories........................................................26
9Troubleshooting..........................................................................27
10 Service .........................................................................................29
11 Waste disposal ............................................................................29
12 Further information.....................................................................29

3 OPO-1-BA-en-2111
1 Before use
1.1 General information
The packaging must be opened carefully to prevent the accessories inside from falling
to the floor and breaking.
In general, a microscope should always be handled with great care, as it is a sensitive
precision instrument. Avoiding abrupt movements during operation or transport is
therefore particularly important, especially in order not to endanger the optical
components.
Likewise, you should avoid dirt or fingerprints on the lens surfaces, as this will reduce
image clarity in most cases.
If the performance of the microscope is to be maintained, it must never be
disassembled. Components such as objective lenses and other optical elements
should therefore be left as they are found at the start of operation. Also the electrical
part at the back and at the bottom of the instrument must not be tampered with without
further ado, because here there is the additional danger of triggering an electric shock.
1.2 Notes on the electrical system
Before connecting to a power supply, be sure to use the correct input voltage. The
power cord selection guide is located on the back of the unit, just above the power
jack. Failure to follow these instructions may result in fire or other damage to the unit.
Also, the main power switch should be turned off before connecting the power cord.
This will prevent an electric shock from occurring.
If you use an extension cord, the power cord you use must be grounded.
If the original fuse blows, replace it only with a suitable fuse. Suitable replacement
fuses are included in the scope of delivery.
All handling of the equipment that involves contact with the electrical system, such as
changing lamps or fuses, may only be carried out when the power supply is
disconnected.

OPO-1-BA-en-2111 4
1.3 Storage
Avoid exposing the device to direct sunlight, high or low temperatures, shock, dust and
high humidity.
The suitable temperature range is 0 - 40° C and a relative humidity of 85 % should not
be exceeded.
The device should always be placed on a firm, smooth and horizontal surface.
When the microscope is not in use, it is best to cover it with the dust cover provided.
The power supply should be switched off at the main switch and the power cord
removed. When storing the eyepieces separately, it is essential to attach the protective
caps to the tube sockets. Dust or dirt inside the optics of a microscope can in many
cases cause irreversible malfunctions or damage.
Accessories consisting of optical elements, such as eyepieces and objectives, are
preferably stored in a drying box with desiccant.

5 OPO-1-BA-en-2111
1.4 Maintenance and cleaning
In any case, the device must be kept clean and regularly cleaned of dust.
Before wiping down the unit when wet, make sure that the power is turned off.
Glass components should preferably be wiped lightly with a lint-free cloth when
contaminated.
To wipe off oil stains or fingerprints from lens surfaces, the lint-free cloth is moistened
with a mixture of ether and alcohol (ratio 70 / 30) and then used for cleaning.
Ether and alcohol must always be handled with care as they are highly flammable
substances. Therefore, it is essential to keep them away from open flames and
electrical appliances, which are switched on and off, and use only in well-ventilated
rooms.
However, organic solutions of this type should not be used to clean other components
of the device. This could result in changes to the paintwork. It is sufficient to use a
neutral cleaning agent for this purpose.
Other cleaning agents for the optical components include:
•Special cleaner for optical lenses
•Special optical cleaning cloths
•Bellows
•Brush
With proper handling and regular inspection, the microscope will operate smoothly for
many years.
However, if a repair is necessary, contact your KERN dealer or our Technical Service.

OPO-1-BA-en-2111 6
2 Nomenclature
Eyepieces
Microscope head / tube
Locking screw
Microscope head
LED incident light
unit
Dimmer
Coarse and
fine drive
Field lens with
field diaphragm
Centering screw
Condenser
Condenser with
aperture adjustment
and swing-out lens
Object table
Lens
Objective
nosepiece
Camera adapter
connector

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Rear view
Carrying
handle
Coarse
and fine
drive
Main switch
Mains
connection
Fuse
LED incident light unit
Power cable
for incident

OPO-1-BA-en-2111 8
Analyzer unit / Reflected light unit
Analyzer
Lambda / Quartz
Wedge Shifter
Bertrand lens
Aperture diaphragm
Insert for diffuser
Lamp housing
Color filter
Polarizer
Luminous field
diaphragm

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3 Technical data / equipment
Dimensions Product:
500x200x500 mm
Dimensions Packing:
520x470x430 mm
Net weight:
13 kg
Gross weight:
16 kg
Input voltage:
AC 100-240V, 50-60Hz
Output voltage:
DC 1.2-6V
Fuse:
2A 5x20mm

OPO-1-BA-en-2111 10

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4 Assembly

OPO-1-BA-en-2111 12
4.1 Analyzer unit (+ reflected light unit)
First, the lamp housing and the incident light unit must be brought together at their
connection points. Then the connection is fixed via an Allen screw on the right at the
connection point of the lamp housing.
Analyzer, polarizer and color filter slides can now be placed in the appropriate slots
(see page 8).
To subsequently attach the incident light unit to the microscope, first loosen the
fastening screw at the tube connection point and remove the black protective cover.
The round dovetail mount on the incident light unit can now be inserted into the round
dovetail mount on the housing and fixed with the fixing screw. Always make sure that
the lenses are not touched with bare fingers and that no dust enters the openings.
Finally, the power cable must be used to make the connection between the lamp
housing and the connection socket on the back of the microscope.
4.2 Microscope head
First loosen the fixing screw at the connection point of the incident light unit and remove
the black protective cover.
The round dovetail mount on the head can now be inserted into the round dovetail
mount on the incident light unit and fixed with the fixing screw. Always make sure that
the lenses are not touched with bare fingers and that no dust enters the openings.
4.3 Objective
The stage must be in the lower position so that the objectives can be screwed into the
revolving nosepiece. The objectives can now be screwed into the revolving nosepiece
in such a way that the objective with the next higher magnification appears when the
revolving nosepiece is turned clockwise. Care should be taken not to touch the lenses
with bare fingers and not to allow dust to enter the apertures.

13 OPO-1-BA-en-2111
4.4 Eyepieces
Always use eyepieces with the same magnification for both eyes. These are simply
placed on the tube sockets after first removing the protective plastic caps. There is no
fixation possibility. You should always make sure that the lenses are not touched with
your bare fingers and that no dust enters the openings.
4.5 Condenser (Swing-Out) / Transmitted Light Polarizer
The object stage should best be brought into the uppermost position using the coarse
drive. With the focus wheel of the condenser one must now bring the condenser carrier
into a middle position. This way, the condenser can be inserted into the condenser
carrier at the appropriate position and fixed with the locking screw. The scale should
be readable from the front. Avoid touching the optical lenses with your bare fingers.
The transmitted-light polarizer (incl. scale) is located on the underside of the
condenser. It is fixed to the side of the condenser by means of an Allen screw. When
loosening this screw, the polarizer can be turned in both directions.
For item 6 (camera connection), see Chapter 8 Using Optional Accessories.
5 Operation
5.1 First steps
The first thing to do is to connect the power supply by means of a mains plug. The
light intensity control (dimmer) should first be set to a low level, so that the eyes
are not immediately exposed to too much light when looking into the eyepieces for the
first time. Now the illumination can be switched on via the main switch.
The next step is to place an object or slide with specimen on the round turntable.
This object must be appropriately prepared so that it is suitable for the use of polarized
transmitted and/or reflected light. The slide can be fixed on the stage using the
specimen holders. The specimen must be placed so that it lies in the beam path and
can be observed.

OPO-1-BA-en-2111 14
5.2 (Pre-) Focusing
In order for an object to be observed, it must be at the correct distance from the lens
so that a sharp image can be obtained.
To find this distance initially (without any other presettings of the microscope), bring
the objective with the lowest magnification into the beam path, look with the right eye
through the right eyepiece and turn the coarse adjustment knob slowly at first (see
illustration).
The simplest method for this would be to bring the stage (also using the coarse drive)
to just below the lens beforehand and then slowly lower it. As soon as an image (no
matter how sharp) can then be seen, the correct sharpness should only be set with the
fine drive.
Torque adjustment of coarse and fine drive
Next to the left adjusting wheels of the coarse and fine drive is a ring which can be
used to change the torque of these wheels. Turning clockwise decreases the torque
and turning counterclockwise increases the torque.
This function can be used to facilitate the focus adjustment on the one hand and to
prevent the object stage from sliding down unintentionally on the other hand.
Important
To avoid damage to the focusing system, never turn the left and right dials of the coarse
and fine focus knobs in opposite directions at the same time.

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5.3 Adjusting the eye relief
In binocular viewing, the interpupillary distance
must be precisely adjusted for each user to obtain
a clear image of the object.
While looking through the eyepieces, hold the left
and right tube housings with one hand each. By
pulling them apart or pushing them together, the
interpupillary distance can be either increased or
decreased (see illustration). As soon as the field of
view of the left eyepiece and the field of view of the
right eyepiece overlap completely, or merge into a
single circular image, the correct interpupillary distance has been set.
5.4 Diopter compensation
The visual acuity of the eyes of a person using the microscope can very often show
minor differences, which are inconsequential in everyday life, but can cause problems
with regard to exact focusing when using the microscope.
This difference can be compensated for by a mechanism on the left tube connector
(dioptric compensation ring) as follows.
1. Move right diopter adjustment ring to position 0.
2. Look through the right eyepiece with the right eye and focus the image using the
coarse and fine focus adjustment knobs.
3. Now look through the left eyepiece with the left eye and focus the image using the
left diopter compensation ring.
To do this, turn the ring in both directions (see illustration) to find out at which
position the image appears sharpest.

OPO-1-BA-en-2111 16
5.5 Centering of the microscope stage
In order to analyze certain objects using the polarization method, it is important to be
able to rotate the microscope stage. This allows the contrast of the object to be
observed as a function of its angular position between the polarizer and the analyzer.
For optimal results, the center of the rotation axis of the stage must be aligned with the
center of the optical path.
The microscopes of the OPO-1 series are correctly adjusted at the factory. However,
it is recommended to check the centering of the microscope stage before first use and
regularly thereafter.
In the event of decentering, the following steps must be carried out.
Centering screw
Centering screw
screw

17 OPO-1-BA-en-2111
1. 10x Bring the objective into the beam path.
2. Make sure that an eyepiece with scale is in (one of) the tube sockets.
is appropriate.
3. Place a suitable microscope slide on the stage.
This should preferably be equipped with a micro reticle.
However, it is also possible to use a point-rich object where one of these points is of such a
magnitude that it roughly coincides with the center of the eyepiece scale in the field of view of
the eyepiece(s).
4. Position the slide so that when looking through the eyepiece(s), the center of
the crosshairs is at the center of the eyepiece scale.
5. Make sure that the fixing screw of the table is loosened so that the table can
be turned.
If the table cannot be turned or can only be turned with difficulty even though the fixing screw
has been loosened, this is an indication that the table is clearly off-centre.
6. If the table is perfectly centered, observe that during a full rotation of the table,
these two centers always remain on top of each other.
The process would thus be complete.
7. If the stage is not centered, one observes that the center of the crosshairs
moves away from the center of the eyepiece scale right at the beginning of the
rotation of the stage and does not coincide with it again until after one full
rotation.
8. Estimate the center of this circular motion made by the crosshairs and move
the slide so that the center of the crosshairs is brought to this estimated
center.
9. Operate the two centering screws so that the center of the crosshairs and the
center of the eyepiece scale are now aligned again.
10.Repeat steps 6 - 9.

OPO-1-BA-en-2111 18
5.6 Setting the magnification
After pre-focusing using the objective with the lowest magnification (see section 5.2),
the total magnification can now be adjusted as required using the revolving nosepiece.
By rotating the revolver, any of the four other objectives can be brought into the beam
path.
It is essential to observe the following points when adjusting the revolving nosepiece:
- The desired lens must always be properly
engaged.
- The turret should not be rotated by holding it by
the individual lenses, but by the silver ring above
the lenses (see illustration).
- When rotating the turret, always make sure that the objective lens that is being
brought into the beam path does not come into contact with the specimen slide.
This can cause considerable damage to the objective lens.
It is best to always check from the side whether there is sufficient clearance. If this
is not the case, the object table must be lowered accordingly.
If you have focused the object of observation for a certain magnification, the focus can
easily get out of focus when selecting the objective with the next higher magnification.
In this case, the focus must be restored by slightly adjusting the fine adjustment knob.

19 OPO-1-BA-en-2111
5.7 Using the eyecups
The eyecups included in the scope of delivery can basically always be used, as they
shield disturbing light that is reflected from light sources in the surroundings at the
eyepiece, thus resulting in better image quality.
But mainly, if eyepieces with a high viewpoint (especially suitable for eyeglass wearers)
are used, then it can be useful for users without glasses to attach the eyecups to the
eyepieces.
These special eyepieces are also called High Eye Point eyepieces and can be
recognized by a glasses symbol on the side. They are also identified by an additional
"H" in the article description (example: HSWF 10x Ø 23 mm).
With the OPO-1 series, the eyecups are already attached to the eyepiece. To use
them, simply unfold the folded rubber parts.
When unfolding the eyecups, care should be taken not to adjust the diopter setting.
Therefore, it is recommended to hold the diopter adjustment ring of an eyepiece with
one hand while unfolding the eyecup with the other.
Eyeglass wearers must fold in the eyecups before observing if there are any on the
High Eye Point eyepieces.
Since the eyecups are made of rubber, it is important to note that they can easily
become contaminated by grease residues during use. To maintain hygiene at all times,
it is therefore recommended to clean the eyecups regularly (e.g. with a damp cloth).
Eyecups
High Eye Point Eyepiece
(recognizable by the glasses symbol)