Kern OBN 141 Operating instructions

KERN OBN 141 is a fluorescence microscope designed for use in biological and medical laboratories, universities, and research institutions. It offers bright and detailed images with its high-quality optics and advanced illumination system. With its fluorescence capability, it allows users to visualize and analyze specific structures or substances within cells and tissues. The device is user-friendly and provides precise control over focus, magnification, and illumination, making it suitable for various applications in life sciences and biomedical research.

पीडीएफ

दस्तावेज़

KERN & Sohn GmbH

Ziegelei 1 Tel: +49-[0]7433- 9933-0

D-72336 Balingen

E-mail: [email protected]

Fax: +49-[0]7433-9933-149

Internet: www.kern-sohn.com

User instructions

Fluorescence microscope

KERN OBN-14

OBN 141, OBN 147, OBN 148

Version 1.0

01/2015

OBN-14-BA-e-1510

KERN OBN-14

Version 1.0 01/2015

User instructions

Fluorescence microscope

Table of contents

1 Before 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

2 Nomenclature ............................................................................... 7

3 Technical data / Features ............................................................ 9

4 Assembly .................................................................................... 11

4.1

Microscope head .................................................................................................................... 12

4.2

Objectives ............................................................................................................................... 12

4.3

Eyepieces ................................................................................................................................ 12

4.4

Colour filter ............................................................................................................................. 12

4.5

Condenser ............................................................................................................................... 13

5 Operation .................................................................................... 13

5.1

Getting started ........................................................................................................................ 13

5.2

(Pre-) focussing ...................................................................................................................... 14

5.3

Adjusting the interpupillary distance ................................................................................... 15

5.4

Dioptre adjustment ................................................................................................................. 15

5.5

Adjusting the magnification .................................................................................................. 16

5.6

Adjusting the Koehler illumination ....................................................................................... 17

5.7

Using eye cups ....................................................................................................................... 20

5.8

Using oil immersion objectives ............................................................................................ 21

5.9

Fluorescence reflected light unit .......................................................................................... 22

6 Changing the bulb ..................................................................... 33

7 Changing the fuse ...................................................................... 33

8 Using optional accessories ....................................................... 34

8.1

Polarisation unit ..................................................................................................................... 34

8.2

Camera connection ................................................................................................................ 35

8.3

Dark field units ........................................................................................................................ 35

8.4

Phase-contrast units .............................................................................................................. 36

9 Trouble shooting ........................................................................ 39

10 Service ........................................................................................ 41

11 Disposal ...................................................................................... 41

12 Further information .................................................................... 41

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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.

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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.

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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.

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NOTE:

The Fluorescence microscopes of the series OBN-14 can be divided into two main components:



Compound microscope (KERN Professional Line)



Fluorescence reflected light unit

The following user manual refers at first merely to the compound microscope.

The disquisition on the fluorescence reflected light unit is carried out at the end of chapter 5. Operation .

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2 Nomenclature

Eyepiece

Tube connectors with dioptre adjustment ring

Camera adapter connection with adjusting screw

Microscope head /

Tube

Trinocular toggle rod

Nosepiece

Objective

Object holder

Specimen stage

Condenser

Aperture adjustment

Condenser

Centring screw

Condenser

Adjusting screw

Microscope head

Control dial

– Y axis

Specimen stage

Dimmer

Field lens with

Field diaphragm

Centring screw

Condenser

Fine adjustment knob

Adjusting screw

Condenser

Coarse adjustment knob

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Rear view

Carrying handle

Main switch

Power connection

Adjusting ring torque

Fuse

Coarse adjustme nt knob

Fine adjustment knob

Condenser

Focus dial

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3 Technical data / Features

Modell

KERN

Optical system Tube

Standard configuration

Illumination

OBN 141 Infinity Trinocular LED + 3W-LED Epi Fluorescence (B/G)

Trinocular

Halogen + 100W Epi Fluorescence (B/G)

Halogen + 100W Epi Fluorescence (B/G/UV/V)

OBN 147 Infinity

OBN 148

Eyepieces:

Infinity

WF 10x / Ø 20 mm

4x / 10x / 20x / 40x / 100x Objectives:

Product dimensions:

Packaging dimensions:

Net weight:

Gross weight:

Input voltage:

Output voltage:

Fuse:

970x345x440 mm

530x220x490 mm

17 kg

23 kg

AC 100-240V, 50-60Hz

DC 1.2-6V

2A 5x20 mm

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OBN-14-BA-e-1510 10

4 Assembly

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4.1 Microscope head

First 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 head 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.

4.2 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 ar e marked “OIL”, you must use an immersion oil with the lowest level of inherent fluorescence.

4.3 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.

4.4 Colour filter

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.

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4.5 Condenser

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 6 (Polarisation unit) and 7 (Camera connection), please see Chapter

8 Use of optional accessories.

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 must be facing upwards. You can fix the object holder to the table using the slide holder (see illustration on the left) . 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) .

You can position a total of two object holders at the same time.

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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.

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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.

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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.

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5.6 Adjusting the Koehler illumination

To make sure that perfect image results are achieved during microscopic observation, it is important that the direction of light of the microscope is optimised. If, as with the devices in the KERN OBN-14 series, the lighting can be set in accordance with Koehler, the result is homogenous illumination of the slide and avoidance of disruptive stray light.

The necessary control elements for this are:



Height-adjustable and centre-adjustable condenser with aperture diaphragm



Field diaphragm

When adjusting the Koehler lighting for the first time, you must first select the lowest possible objective magnification, so that you can carry out the following steps.

1. Use the condenser focus wheel to position the condenser directly below the specimen stage. Switch on the lighting and use the coarse and fine adjustment knob to bring the slide with the cover glass positioned facing upwards into focus.

2. Close the field diaphragm completely using its adjusting ring. When you look in the microscope a blurred image appears in the aperture. If the microscopic image is completely dark, the image for the field diaphragm is outside the field of view and must be brought into the field of view using the centring screws on the condenser.

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3. Adjust the height of the condenser until the image from the field diaphragm appears clearly in the field of view. For some microscopes there is a risk that you will lift the condenser up so high that it collides with the object holder.

Therefore care is needed when doing this.

4. Use the centring screws of the condenser holder to bring the image from the field diaphragm into the centre of the field of view.

5. Open the field diaphragm until it just disappears out of the field of view.

If necessary, simply re-centre using the centring screws on the condenser holder.

OBN-14-BA-e-1510 18

6. Use the aperture diaphragm of the condenser to find the very best compromise between contrast and resolution for the microscopic image. The scale divisions on the condenser can be used as a guideline. Select in accordance with the objective being used.

The view in the tube without the eyepiece should look something like the illustration on the right.

The diameter of the aperture diaphragm which is then visible should make up approximately 2/3 of the pupil diameter.

If the eyepiece should be removed, for checking, then please make sure that no dirt or dust falls into the tube.

7. It is possible to alter the brightness of the bulb using the dimmer . The brightness is always controlled by the bulb brightness and not by the aperture diaphragm.

8. Possibly there is the need of re-adjusting the focus and x-y axis.

9. Observe the object.

If another magnification is selected afterwards, then the Koehler illumination does not have to be reset from scratch, only the aperture diaphragm and field diaphragm need to be adjusted as required.

As a result you can always check whether the condenser needs to be re-centred.

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5.7 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 user s 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)

OBN-14-BA-e-1510 20

5.8 Using oil immersion objectives

The 100x objectives of the OBN-14 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.

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5.9 Fluorescence reflected light unit

There are samples, which can be excited by light beams and thereby show emissions, which have different wave lengths than the previous excitation beams.

The wave length of the emission is always bigger than the wave length of the excitation (Stokes shift). This process is called fluorescence and can serve as the base of a microscopic contrasting method. For the most common way to realise this, an upright light microscope is extended by a fluorescence reflected light unit.

Principle

Depending on the sample there is an excitation light needed, that is contained in the spectrum of the light source (HBO or LED). The excitation filter is only permeable for the according wave length. After that the excitation light hits a dichroic mirror, which reflects it towards the objective and the sample. After the sample absorbed the excitation light, the emission of the fluorescent light occurs (with a bigger wave length than the excitation light). The part of the fluorescent light, which is beamed into the objective, can pass the dichroic mirror. The dichroic mirror additionally prevents the remaining part of the excitation light from advancing towards the eyepieces. The barrier filter finally eliminates all wave ranges out of the beam path not belonging to the observed fluorescence. Thus the resulting image is just developed by the fluorescent light emitted from the sample.

OBN-14-BA-e-1510 22

Overview of wave lengths for excitation and emission per excitation filter

Blue line: Wave length excitation

Green line: Wave length emission

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Nomenclature (components)

Protective plate

Cover for FL module

Fixing Allen screw for microscope head

Main body

Connection point for microscope head

Fixing screw for lamp housing

HBO/LED lamp housing

Power connection

Screw for attaching the protective plate

Connection point for microscope housing

Allen wrench

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Nomenclature (control elements)

Control wheel for FL module

Centring device for field diaphragm

Control lever for field diaphragm

Centring device for aperture diaphragm

Control lever for aperture diaphragm

Condenser control

Screw for cover of lamp housing

Centring screw for lamp (vertical)

Centring screw for lamp (horizontal)

Control lever for illumination

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Nomenclature (Power supply unit for HBO lamp)

Basic data

There are two different fluorescence reflected light units available for the microscopes of the series OBN-14. They have the following specifications.

Article number

Illumination Excitation filter

Centring objective

Input voltage power supply unit

OBB-A1155 100W HBO UV / V / B / G Yes 100-240V

100W HBO B / G Yes 100-240V OBB-A1153

OBN-14-BA-e-1510 28

Assembly

In order to assemble the fluorescence reflected light unit correctly and mount it afterwards to the microscope housing, the following steps have to be carried out.

1. When the microscope is already assembled without the FL unit, you have to remove the microscope head at first.

2. Tip the main body of the FL unit to the side and mount the protective plate to the appropriate location on the underside.

3. Attach the main body to the therefore intended connection point of the microscope housing and fix it with the screw.

4. Unite the lamp housing and the main body by their connection points and fix it with both screws.

5. Attach the microscope head to the main body and fix it with the Allen screw.

6. Install the connecting cable between lamp housing and power supply unit.

7. Establish the power supply by attaching the mains cable.

Operation

Before you use the reflected light unit for special fluorescence applications, it will be favourable to adjust the microscope in the bright field mode. This includes the placing of the sample, adjusting the interpupillary distance, pre-focussing, dioptre adjustment, etc. After that you can go on with the usage of the fluorescence reflected light unit.

1. When using a HBO lamp at first there must be ensured, that the control lever for the illumination is slid-in.

2. Establish the power supply. When using a HBO lamp, check the setting of the input voltage by using the appropriate slide on the rear of the power supply unit

(100V/240V).

3. Press the main switch. When using a HBO lamp, you have to press the ignition after that in order to illuminate the lamp. It lasts about 15 minutes until the lamp has gained a maximum and stable illuminating power.

4. After placing the sample you can bring the needed objective into the beam path.

5. Choose the right position of the control wheel for the FL module.

6. When using a HBO lamp, now the control lever for the illumination can be pulled out.

7. Start the observation.

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Control elements for illumination

The following control elements for the illumination play a role within the fluorescence microscopy:



Field diaphragm, aperture diaphragm, condenser:

Optimisation of the contrast and the light yield.



Control lever for illumination:

When located at the medium position there is a filter, which softens the lighting, so that samples, which are not stable enough for the full illuminating power, can be observed as well.

Important warnings for the usage of a HBO lamp



During operation the lamp is showing a strong heat development. It should be avoided to come into contact with the lamp housing while and after some time of running the reflected light unit.



The lamp must not in any circumstances be switched off during the preheating. It could cause a significant reduction of the lamps life time.



Equally the lamp must not be switched on directly after a switch-off process.



When pausing the observation you should always slide in the control lever for the illumination in order to interrupt the light beam. The light spectrum of the HBO lamp often can be harmful for microbes.



Never look inside the eyepieces when the beam path is opened (by the control lever for illumination) and there is set an empty position of the FL module at the same time. There is the risk of blinding.



A HBO lamp has a certain life time. The closer you push it to its limit, the bigger the risk of an explosion of the lamp and setting free of toxic mercury vapour. This must be avoided at all costs.

The following devices can provide information about the necessity of a lamp replacement (This applies for 100W HBO lamps): o Ampere meter on the power supply unit

As soon as 4.8 A are reached  lamp replacement o Life time display on the power supply unit

As soon as 100 h are reached  lamp replacement

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Centring the lamp (HBO)

When running the HBO lamp for a long time there is the possibility, that the holder of the lamp is moving out of its centre due to the strong heat development. This circumstance has to be corrected when it appears, because therefore the field of view is no longer equally illuminated.

1. Screw in the centring objective on the nosepiece instead of a standard objective.

2. Position the centring objective into the beam path.

3. Set FL module to position G (for this setting there is a relatively subdued light, convenient for the eyes).

4. When looking into the eyepieces, there is appearing a hair cross and the decentred light spot (also in cross shape).

5. Use the two centring screws on the lamp housing for moving the light spot into the centre of the hair cross. (Warning: Heat development on the lamp housing).

Changing the lamp (HBO)

1. Disconnect the FL reflected light unit from the power supply.

2. Check if the lamp housing has cooled down.

3. Loosen the screw for the cover of the lamp housing (only when it is cool).

4. Carefully flip out the lamp holder.

5. Loosen the two fixing screws for the HBO lamp.

6. Replace the old lamp by a new one.

7. Tighten the fixing screws again.

8. Close the cover and fix it with the screw.

The new installed spare lamp may under no circumstances be touched with naked hands. Impurities will benefit the risk of explosion during operation.

If there should be nevertheless impurities, the lamp has to be cleaned. We recommend for this purpose to use a lint-free cloth soaked with an ether alcohol mixture (Proportion: 70/30).

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Changing the fuse

The fuse housing is on the rear of the power supply unit next to the mains power supply socket. With the device switched off and unplugged, you can screw out the housing. The defective fuse can be removed from its housing and be replaced with a new one.

After that, you just need to insert the fuse housing back into the insertion point next to the mains power supply socket.

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6 Changing the bulb

Halogen

You must not attempt to change the bulb immediately after the microscope has been used, as the bulb will still be hot and so there is a risk that the user could be burnt.

Before changing the bulb the device must be switched off and unplugged.

To change the bulb, tip the device carefully to the back or side. When doing this, please make sure that all microscope components are firmly fixed. The bulb holder is on the underside of the device. It can be opened by undoing the screws on the holder

(see illustration) . We recommend that here you should also test again, to check that heat is no longer being produced. The defective bulb can be pulled out of the socket and be replaced with a new one. After the bulb holder has been replaced in the underside of the device and the screws replaced, the bulb replacement procedure is complete.

Important:

When fitting the new bulb into the socket, it must only be handled with sterile gloves or using the bulb packaging film. Grease and dust residue can have a negative effect on the light quality and service life.

7 Changing the fuse

The fuse housing is on the rear of the microscope below the mains power supply socket. With the device switched off and unplugged, you can pull out the housing.

When doing this, it is helpful to use a screwdriver or similar tool. The defective fuse can be removed from its housing and be replaced with a new one.

After that, you just need to insert the fuse housing back into the insertion point below the mains power supply socket.

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8 Using optional accessories

8.1 Polarisation unit

The polarisation unit consists of a polariser and an analyser.

Both consist of a round glass plate with an external holder ring. To mount the analyser there is a slider with a socket fitted on the front of the microscope directly below the nosepiece (see illustration on page 10) , where you can simply insert the analyser (see left illustration) .

The polariser on the other hand is only placed on the ring holder of the field lens (see right illustration) .

There are two points to take into account when subsequently using the polarisation unit:



The aperture setting of the condenser must be in position PH .



For its starting position, the polariser must be turned to the position in which you can see the highest level of darkness in the field of view (without object slide).

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8.2 Camera connection

Due to the trinocular tube, which is a standard fitting for the whole OBN-14 series, it is possible to connect microscope cameras to the device, in order to digitally record images or sequences of images of an object being observed.

After the plastic cover has been removed from the camera adapter connector on the top of the microscope head, then a suitable adapter must be fitted.

In general there are two C-mount adapters available for this (1x and 0.57x magnification, see Chapter 3 Features ). After fitting one of these adapters it can be fixed with the fixing screw. A camera which has a C-mount thread is then screwed on top of the adapter.

We recommend that you first adjust the field of view using the eyepieces on the device for the existing requirements, and then carry out the observation using the microscope camera (i.e. using the PC screen which is connected).

To do this, the trinocular toggle rod on the righthand side of the microscope head must be pulled out. The light from the microscope lighting is deflected so that it is completely in the beam path for the camera, which causes a dark field of view in the eyepieces. This means that it is not possible to simultaneously observe by the eyepieces and PC screen.

For C-mount adapters, which have their own integrated magnification, the image which is shown on the camera connected to the device can often have a different level of focus compared with the image on the eyepiece.

In order to be able to bring both images into focus, the focus can be adjusted by those adapters.

8.3 Dark field units

There is the following way to carry out dark field applications.

1. A special dark field condenser can be used in place of the standard condenser.

This as a paraboloid construction and also meets the requirements of professional application fields, in contrast to a dark field attachment.

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8.4 Phase-contrast units

Fundamentally there are two different ways for you to conduct the phase-contrast procedure. A simple method and a more comprehensive method.

1. Simple phase-contrast unit

This consists of a simple PH condenser, a PH objective with a specific magnification (10x, 20x, 40x or 100x), a PH slider, which is adapted to the lens being used, a centring telescope and two green filters.

To use this, you need to replace the standard condenser of the microscope with the PH condenser. One of the objectives in the nosepiece is also replaced with the PH objective and this is positioned in the beam path.

OBN-14-BA-e-1510 36

With the surface marked “TOP” facing up, the PH slider is pushed upwards into the insertion point on the PH condenser until it clicks into the first position. At this first position, the phase ring of the PH slider is in the beam path. If the aperture setting on the PH condenser is set to “PH”, then the phase-contrast application can begin. In order to return to the bright field application, you must push the PH slider further to the second click position. At this point there is no PH ring as in position 1; the beam can pass without being affected by the PH slider.

The PH objective has a PH ring in its lens system, just like the PH slider. Due to their size on one hand and their positioning on the other, these two rings must be aligned to one another in the beam path. The position of the ring in the objective cannot be altered, that of the ring in the slider however can be. Although it has been pre-centred, it may still be necessary that after a certain period of use it will need to be re-centred using the three Allen bolts on the side of the slider and the centring telescope. For further information on adjusting the PH rings, please see section 4.9, Point 2 - End.

Depending on the preferences of the user, using a green filter can produce a more effective and pleasant image. To achieve this, the green filter must be screwed onto the underside of the PH condenser.

2. Comprehensive phase-contrast unit

This consists of a PH universal rotary condenser, four PH objectives (10x, 20x,

40x and 100x), a centring telescope, two centring turnscrews and a green filter.

To use this, you need to replace the standard condenser of the microscope with the PH universal rotary condenser. The required objectives are also screwed into the nosepiece and one of these is positioned in the beam path. The two centring turnscrews can be fitted to the relevant points on the sides of the condenser using the screw connection on their spring retainer.

The condenser has a hub with six positioning options. Four of these are fitted with a phase ring, which matches only one specific objective magnification. When doing this you must note the marking on the rotary knob at the relevant position.

The other two positions are intended for bright field applications.

A PH objective has a PH ring in its lens system, just like the individual positions of the PH universal rotary condenser. Due to their size on one hand and their positioning on the other, the two related rings must be aligned to one another in the beam path. The position of the ring in the objectives cannot be altered, that of the rings in the condenser disc however can be.

37 OBN-14-BA-e-1510

The adjustment for this is carried out as follows. a. First adjust the microscope using bright field mode. b.

Move the hub to the required PH position (e.g. “10x”). c. Open the aperture diaphragm on the condenser to its maximum (slider to the left). d. Bring the relevant PH objective (e.g. 10x) into the beam path. e. Place the centring telescope onto one of the two tube connectors, in place of a standard eyepiece. f. Undo the fixing screw of the centring telescope and pull out (move) the front part of the telescope, so that you can focus both phase rings in the field of view. You can also use the focus wheel of the condenser holder when doing this. Then retighten the screws.

In the field of view you will now see the image of a white (condenser) and a black

(objective) ring. The black one is central and the white one possible is pushed to one side (see left illustration) . g. Now press the turnscrews fitted on the side of the condenser towards the centre until they grip the screws. Then by turning the screws and at the same time watching the rings through the centring telescope, move the white ring to the centre (see central illustration) . h. As soon as both the rings overlap each other (see right illustration) the adjustment is successfully completed and can also be carried out for the pairs of rings of the other magnifications. i. After the adjustment, the centring telescope must be replaced by the standard eyepiece, so that you are able to observe the object on the angle table in phase contrast mode.

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9 Trouble shooting

Problem

The bulb does not light

The bulb blows immediately

The field of view is dark

You cannot adjust the brightness

The field of view is dark or is not correctly illuminated

The field of view of one eye does not match that of the other eye

Possible causes

The mains plug is not correctly plugged in

There is no power at the socket

Defective bulb

Defective fuse

The specified bulb or fuse has not been used

The aperture diaphragm and/or field diaphragm are not opened wide enough

The selector switch for the beam path is set to “Camera”

The condenser is not correctly centred

The brightness control has been set incorrectly

The condenser has not been correctly centred

The condenser is too low

The objective is not positioned correctly on the beam path

The selector switch for the beam path is between two settings

The nosepiece is not correctly fitted

The condenser is not correctly fitted

An objective is being used which doesn’t match the lighting area of the condenser

The condenser has not been correctly centred

The field diaphragm is closed too tightly

The bulb is not correctly fitted

The interpupillary distance is not correctly adjusted

Dioptre setting has not been carried out correctly

Different eyepieces are used for the righthand and lefthand side

The eyes are not used to using a microscope

39 OBN-14-BA-e-1510

Problem

Blurred details

Bad image

Bad contrast

Vignetted field of view

Dirt or dust in the field of view

Possible causes

The aperture diaphragm is not opened wide enough

The condenser is too low

The objective does not belong to this microscope

The front lens of the objective is dirty

An immersion object has been used without immersion oil

The immersion oil contains air bubbles

The condenser is not correctly centred

The recommended immersion oil has not been used

Dirt / dust on the objective

Dirt /dust on the front lens of the condenser

Dirt / dust on the eyepieces

Dirt / dust on the front lens of the condenser

Dirt / dust on the object

One side of the image is blurred

The stage was not correctly fitted

The objective is not positioned correctly on the beam path

The nosepiece is not correctly fitted

The upper side of the object is facing down

The image flickers

The coarse adjustment knob is difficult to turn

The nosepiece is not correctly fitted

The objective is not positioned correctly on the beam path

The condenser has not been correctly centred

The rotational resistance brake is too tight

The angle table is blocked by a solid body

The stage moves down on its own

The fine adjustment knob moves on its own

When you move the table, the image becomes blurred

The rotational resistance brake is not tight enough

The stage was not correctly fitted

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10 Service

If, after studying the user manual, you still have questions about commissioning or using the microscope, or if unforeseen problems should arise, please get in touch with your dealer. The device may only be opened by trained service engineers who have been authorised by KERN.

11 Disposal

The packaging is made of environmentally-friendly materials, which you can dispose of at your local recycling centre. Disposal of the storage box and device must be carried out by the operator in accordance with all national or regional laws in force in the location of use.

12 Further information

The illustrations may differ slightly from the product.

The descriptions and illustrations in this user manual are subject to change without notice . Further developments on the device may lead to these changes.

All language versions contain a non-binding translation.

The original German document is the binding version.

41 OBN-14-BA-e-1510

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NOTES

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OBN-14-BA-e-1510 42

नमस्ते! मैं एक AI चैटबॉट हूँ जिसे विशेष रूप से Kern OBN 141 Operating instructions के साथ आपकी सहायता करने के लिए प्रशिक्षित किया गया है. मैंने दस्तावेज़ की अच्छी तरह से समीक्षा की है और आपको आवश्यक सटीक जानकारी का पता लगाने या सामग्री को स्पष्ट और सरल शब्दों में समझाने में मदद कर सकता हूँ. चाहे आप विशिष्ट सुविधाओं, समस्या निवारण चरणों या सामान्य उपयोग पर मार्गदर्शन की तलाश कर रहे हों, अपने प्रश्न पूछने के लिए स्वतंत्र महसूस करें. आप अपनी चिंताओं या ज़रूरतों के बारे में जितनी अधिक जानकारी प्रदान करेंगे, मैं उतनी ही सटीकता और प्रभावी ढंग से आपकी सहायता कर सकता हूँ!

सहायक टाइपिंग कर रहा है

सहायक कीबोर्ड से बाहर है. कृपया, बाद में फिर से प्रयास करें.

विषयसूची

ऐसा लगता है कि आप एक ऐसे दस्तावेज़ पर पहुँच गए हैं जो कई भाषाओं में लिखा गया है, जिसमें एक ऐसी भाषा भी शामिल है जो आपकी मूल भाषा नहीं है. आप अपनी पसंद की भाषा के बिना पृष्ठों को अस्थायी रूप से छिपाने के लिए निम्न लिंक का उपयोग कर सकते हैं.