KERN Optics OKN-1 User manual

OKN-1_OKO-1-BA-e-1510
KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
E-mail: [email protected]
Tel: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
User instructions
Metallurgical microscope
KERN OKN-1, OKO-1
OKN 175, OKN 177
OKO 176, OKO 178
Version 1.0
01/2015

OKN-1_OKO-1-BA-e-1510 2
GB
KERN OKN-1, OKO-1
Version 1.0 01/2015
User instructions
Metallurgical 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 / Features.............................................................................. 9
4Assembly...................................................................................................... 11
4.1 Reflected light unit ............................................................................................................................... 12
4.2 Microscope head................................................................................................................................... 12
4.3 Objectives.............................................................................................................................................. 12
4.4 Eyepieces............................................................................................................................................... 13
4.5 Colour filter............................................................................................................................................ 13
4.6 Condenser ............................................................................................................................................. 13
5Operation...................................................................................................... 14
5.1 Getting started....................................................................................................................................... 14
5.2 (Pre-) focussing..................................................................................................................................... 15
5.3 Adjusting the interpupillary distance.................................................................................................. 16
5.4 Dioptre adjustment................................................................................................................................ 16
5.5 Adjusting the magnification................................................................................................................. 17
5.6 Using eye cups...................................................................................................................................... 18
5.7 Using oil immersion objectives............................................................................................................ 19
5.8 Adjusting the Koehler illumination for transmitted light................................................................... 20
5.9 Adjusting the illumination for incident light ....................................................................................... 23
6Changing the bulb ....................................................................................... 25
6.1 Transmitted light................................................................................................................................... 25
6.2 Reflected light ....................................................................................................................................... 26
7Changing the fuse........................................................................................ 26
7.1 Transmitted light................................................................................................................................... 26
7.2 Reflected light ....................................................................................................................................... 26
8Using optional accessories ........................................................................ 27
8.1 Polarisation unit (Transmitted light).................................................................................................... 27
8.2 Camera connection (only for trinocular version) ............................................................................... 28
8.3 Dark field units (Transmitted light)...................................................................................................... 28
8.4 Phase-contrast units (Transmitted light) ............................................................................................ 29
9Trouble shooting.......................................................................................... 32
10 Service.......................................................................................................... 34
11 Disposal........................................................................................................ 34
12 Further information...................................................................................... 34

3 OKN-1_OKO-1-BA-e-1510
1 Before use
1.1 General notes
You must open the packaging carefully, to make sure that none of the accessories in
the packaging fall on the floor and get broken.
In general, microscopes should always be handled carefully because they are
sensitive precision instruments. When using or transporting the microscope it is
particularly important to avoid abrupt movements, as this may damage the optical
components.
You should also avoid getting dirt or finger prints on the lens surface, because in
most cases this will reduce image clarity.
To maintain the performance of the microscope, it must never be disassembled. So
components such as lenses and other optical elements should be left as they were
before use. Also the electrical parts on the rear and base of the device must not be
tampered with, as in this area there is an additional risk of triggering an electric
shock.
1.2 Notes on the electrical system
Before connecting to a mains power supply, you must make sure that you are using
the correct input voltage. The information to select the correct mains cable is located
on the device, on the rear of the product directly above the connection socket. You
must comply with this information. If you do not comply with these specifications, then
fires or other damage to the device could occur.
The main switch must also be switched off before the mains cable is connected. In
this way you will avoid triggering an electric shock.
If you are using an extension cable, then the mains cable you use must be earthed.
If the original fuse should blow, it must only be replaced by an appropriate fuse.
Suitable replacement fuses are included with the delivery.
When carrying out any procedures whereby you come into contact with the electrical
system of the device, such as, for example, changing the bulb or fuse, only carry out
these procedures when the power is disconnected.

OKN-1_OKO-1-BA-e-1510 4
Under no circumstances should you touch the integrated halogen bulbs either during
operation or directly after use. These bulbs produce significant heat and therefore
there is a risk that the user could be severely burnt. So before handling the bulbs,
you must check that they have cooled down.
The microscope housing, on the other hand, is constructed so that no significant heat
radiation emanates from the device and that there is absolutely no risk of the user
burning themselves from the housing outer surfaces.
1.3 Storage
You should ensure that the device is not exposed to direct sunlight, temperatures
which are too high or too low, vibrations, dust or a high level of humidity.
The ideal temperature range is between 0 and 40°C and a relative humidity of 85%
should not be exceeded.
The device should always be located on a rigid, smooth, horizontal surface.
When the microscope is not being used, you should cover it with the enclosed dust
protective cover. When doing this, the power supply is stopped by switching off at the
main switch and unplugging the mains cable. If the eyepieces are being stored
separately, the protective caps must be fitted to the tube connectors. In most cases,
if dust and dirt gets inside the optical unit of a microscope this can cause irreversible
errors or damage.
The best way to store accessories which consist of optical elements, such as, for
example, eyepieces and objectives, is in a dry box with desiccant.

5 OKN-1_OKO-1-BA-e-1510
1.4 Maintenance and cleaning
In any event, the device must be kept clean and dusted regularly.
If any moisture should be occur, before you wipe down the device you must ensure
that the mains power is switched off.
When glass components become dirty, the best way to clean them is to wipe them
gently with a lint-free cloth.
To wipe oil stains or finger prints off the lens surface, moisten the lint free cloth with a
mixture of ether and alcohol (70 / 30 ratio) and use this to clean the lens.
You must be careful when handling ether and alcohol, as these are highly flammable
substances. You must therefore keep it away from naked flames and electrical
devices which can be switched on and off, and only use it in well-ventilated rooms.
However organic solutions of this type should not be used to clean other components
of the device. This could lead to damage to the paint finish. To do this, it is sufficient
to use a neutral cleaning product.
You could also use the following cleaning products to clean the optical components:
Special cleaner for optical lenses
Special optical cleaning cloths
Bellows
Brush
When handled correctly and checked regularly, the microscope should give many
years of efficient service.
Should repairs still be necessary, please contact your KERN dealer or our Technical
Department.

OKN-1_OKO-1-BA-e-1510 6
2 Nomenclature

7 OKN-1_OKO-1-BA-e-1510
Rear view

OKN-1_OKO-1-BA-e-1510 8
Reflected light unit

9 OKN-1_OKO-1-BA-e-1510
3 Technical data / Features
Eyepieces:
WF 10x / Ø 18 mm
Objectives OKN-1:
5x / 10x / 20x LWD / 40x LWD
Objectives OKO-1:
5x / 10x / 100x / 20x LWD / 40x LWD
Product dimension:
OKN 175, OKO 176
490x200x460 mm
Product dimension:
OKN 177, OKO 178
550x200x460 mm
Packing dimensions:
OKN 175, OKO 176
750x360x450 mm
Packing dimensions:
OKN 177, OKO 178
990x360x450 mm
Net weight:
OKN 175, OKO 176
13 kg
Net weight:
OKN 177, OKO 178
14,5 kg
Gross weight:
OKN 175, OKO 176
17 kg
Gross weight:
OKN 177, OKO 178
21 kg
Input voltage:
AC 100-240V, 50-60Hz
Output voltage:
DC 1,2-6V
Fuse:
2A 5x20mm

OKN-1_OKO-1-BA-e-1510 10

11 OKN-1_OKO-1-BA-e-1510
4 Assembly

OKN-1_OKO-1-BA-e-1510 12
4.1 Reflected light unit
At first you have to unite the lamp housing and the reflected light unit on their
connection points. After that the connection has to be fixated by an Allen screw,
which is attached to the right-hand side of the connection point of the lamp housing.
Now the slides for analyser, polariser and colour filter can be attached to the
appropriate slots (see page 8).
Afterwards in order to install the reflected light unit to the microscope, you must
loosen the fixing screw on the tube connection point and remove the black protective
cover.
You can then insert the round dovetail bracket on the light unit into the round dovetail
bracket on the housing and fix it with the fixing screw. When doing this, you should
always make sure that you do not touch the lenses with your bare fingers and that no
dust enters the apertures.
Finally you must establish the electrical connection between power supply unit and
reflected light unit. The plug of the connection cable, attached to the rear of the light
unit has to be installed to the socket on the rear of the power supply unit. Please do
also use the screw lock on the plug.
4.2 Microscope head
First you must loosen the fixing screw on the tube connection point of the reflected
light unit and remove the black protective cover.
You can then insert the round dovetail bracket on the head into the round dovetail
bracket on the reflected light unit and fix it with the fixing screw. When doing this, you
should always make sure that you do not touch the lenses with your bare fingers and
that no dust enters the apertures.
4.3 Objectives
The specimen stage must be in its lowest position so that the objectives can be
screwed into the nosepiece. You can then screw the objectives into the nosepiece so
that when you turn the nosepiece in a clockwise direction, the objective with the next
strongest magnification appears. You must make sure that you do not touch the
lenses with your bare fingers and that no dust enters the apertures. For objectives
which are marked “OIL”, you must use an immersion oil with the lowest level of
inherent fluorescence.

13 OKN-1_OKO-1-BA-e-1510
4.4 Eyepieces
You must always use eyepieces with the same magnification for both eyes. These
are simply placed onto the tube connectors, once you have first removed the plastic
protective caps. There is no way of fixing them. You should always make sure that
you do not touch the lenses with your bare fingers and that no dust enters the
apertures.
4.5 Colour filter
OKO-1
A blue colour filter is already an integral part of the condenser. It is screwed onto the
underside using a ring bracket. It can be removed at any time. In order to use
suitable filters without this holder ring, these can simply be placed in the ring bracket
of the field lens.
4.6 Condenser
OKO-1
We recommend that you use the course adjustment knob to bring the specimen
stage to its uppermost position. Use the focus dial of the condenser to move the
condenser holder to the central position. In this way the condenser can be fitted at
the right place in the condenser holder and fixed with the adjusting screw. When
doing this, you should be able to read the scale from the front. You should avoid
touching the optical lenses with bare fingers.
For points 7 (Polarisation unit) and 8 (Camera connection), please see Chapter
8 Use of optional accessories.

OKN-1_OKO-1-BA-e-1510 14
5 Operation
5.1 Getting started
The very first step is to establish a power connection using the mains plug. You
should first adjust the dimmer to a low level, so that when you look through the
eyepiece for the first time, your eyes are not immediately subject to a high level of
light. You can now switch on the lighting using the main switch.
The next step is to place an object holder with the sample on the angle table. To do
this, the cover glass (if used) must be facing upwards. For the models of the series
OKO-1 you can fix the object holder to the table using the slide holder (see
illustration on the left). You can position a total of two object holders at the same
time.
To move the sample into the beam path, you must use the adjustment wheels on the
right of the angle table (see illustration on the right).

15 OKN-1_OKO-1-BA-e-1510
5.2 (Pre-) focussing
When you are observing an object, you must have the correct distance to the
objective to achieve a sharp image.
In order to find this distance at the beginning (without other default settings of the
microscope) place the objective with the lowest magnification in the beam path, look
through the right eyepiece with the right eye and turn it slowly using the coarse
adjustment knob (see illustration).
The simplest way of doing this would be to first raise the specimen stage (using the
coarse adjustment knob) until it is just under the objective and then lower it slowly. As
soon as an image is recognisable (no matter how sharp), then you should only adjust
the focus using the fine adjustment knob.
Adjusting the torque of the coarse and fine adjustment knob
Next to the left adjustment wheel for the coarse and fine adjustment knob there is a
ring which you can use to alter the torque of these wheels. Turning it in a clockwise
direction reduces the torque and turning it in an anti-clockwise direction increases it.
On one hand, this function can help to make it easier to adjust the focus and on the
other hand it can prevent the specimen stage from slipping down unintentionally.
Important:
In order to avoid damaging to the focussing system, the left and right adjustment
wheels for the coarse and fine adjustment knob must never be rotated at the same
time in opposite directions.

OKN-1_OKO-1-BA-e-1510 16
5.3 Adjusting the interpupillary distance
With binocular viewing, the interpupillary distance
must be adjusted accurately for each user, in
order to achieve a clear image of the object.
While you are looking through the eyepieces, use
your hands to hold the righthand and lefthand tube
housing firmly. By pulling them apart or pushing
them together, you can either increase or reduce
the interpupillary distance (see illustration). As
soon as the field of views of the lefthand and
righthand eyepieces completely overlap each
other, i.e. they combine to form a circular image, then the interpupillary distance is
set correctly.
5.4 Dioptre adjustment
The eye strengths of each eye of the microscope user can often be slightly different,
which in daily life has no consequences. But when using a microscope this can
cause problems in achieving precise focussing.
You can use a mechanism on both tube connectors (dioptre adjustment rings) to
compensate for this as follows.
1. Put the right dioptre adjustment ring to position 0.
2. Look through the right eyepiece with the right eye and bring the object into focus
by using the coarse and fine adjustment knob.
3. Then look through the left eyepiece with the left eye and use the lefthand dioptre
adjustment ring to focus the image.
To do this, you just need to turn the ring in both directions (see illustration), to find
out where the image is at its most focussed.

17 OKN-1_OKO-1-BA-e-1510
5.5 Adjusting the magnification
After prefocussing has been carried out using the objective with the lowest
magnification (see section 5.2), you can then adjust the overall magnification using
the nosepiece, as necessary. By turning the nosepiece you can bring any one of the
four other objectives into the beam path.
When adjusting the nosepiece, you must take the following points into account:
- The required objective must be properly locked in
place at all times.
- The nosepiece should not be rotated by holding
individual objectives, you should use the silver
ring above the objectives (see illustration).
- When rotating the nosepiece you must always make sure that the objective which
is about to be positioned in the beam path does not touch the object holder. This
can lead to significant damage to the objective lens.
We recommend that you always check from the side to make sure that there is
sufficient leeway. If this should not be the case, the specimen stage must be
lowered accordingly.
If you have focussed the object to be observed for a specific magnification, then if
you select the objective with the next greatest magnification, then the object will be
slightly out of focus. Use the fine adjustment knob to make a slight adjustment and
restore the focus.

OKN-1_OKO-1-BA-e-1510 18
5.6 Using eye cups
The eye cups supplied with the microscope can basically be used at all times, as
they screen out intrusive light, which is reflected from light sources from the
environment onto the eyepiece, and the result is better image quality.
But primarily, if eyepieces with a high eye point (particularly suitable for those who
wear glasses) are used, then it may also be useful for users who don’t wear glasses,
to fit the eye cups to the eyepieces.
These special eyepieces are also called High Eye Point eyepieces. They can be
identified by the glasses symbol on the side. They are also marked in the item
description by an additional “H” (example: HSWF 10x Ø 23 mm).
When fitting the eye cups, make sure that the dioptre setting is not moved. We would
therefore advise that you hold the dioptre compensation ring on an eyepiece with one
hand while you fit the eye cup with the other.
Before using the microscope, users who wear glasses must remove the eye cups,
which you may find on High Eye Point eyepieces.
As the eye cups are made of rubber, you must be aware that when you are using
them, they can become slightly dirty through grease residues. In order to maintain
hygiene, we would therefore recommend that you clean the eye cups regularly (e.g.
with a damp cloth).
Eye cups
High Eye Point eyepiece
(identified by the glasses symbol)

19 OKN-1_OKO-1-BA-e-1510
5.7 Using oil immersion objectives
The 100x objectives of the OKO-1 and OKN-1 series are objectives which can be
used with oil immersion (they are always marked with the word “OIL”). Using these
generates a particularly high resolution for microscopic images.
To use oil immersion correctly, please follow these steps.
1. Put a drop of oil on the cover glass (with standard thickness of 0.17 mm) of the
object slide.
2. Lower the specimen stage and position the 100x objective in the beam path.
3. Bring the specimen stage or object slide to the objective very slowly until there is
slight contact.
4. Observe the object.
The object slide and objective must not be pressed against each other. The oil
constitutes the contact layer.
If the contact is made too jerky, there is a chance that existing air bubbles in the oil
cannot escape. This would have a negative impact on image clarity.
After use or before changing the slide, any components which have been in contact
with the oil must be cleaned thoroughly. See also 1.4 Maintenance and cleaning.