KERN OBT Series Compound School Microscopes

Technical Data

Declaration of Conformity

The current EC/EU Declaration of Conformity can be found online at: https://www.kern-sohn.com/shop/de/DOWNLOADS/

Overview of the Device

The KERN OBT series microscopes are precision optical instruments designed for educational and laboratory use. The document provides a detailed overview of the device, including its nomenclature. The main parts identified are:

• 1. Eyepiece
• 2. Tube connectors with diopter adjustment ring
• 3. Microscope head / tube
• 4. Locking screw head
• 5. Coarse drive
• 6. Fine drive
• 7. Setting wheel
• 8. X - Y axis Object table
• 9. Field lens
• 10. Condenser with aperture adjustment
• 11. Object table
• 12. Object holder
• 13. Objective
• 14. Nosepiece (the rotating part holding objectives)

Before Use

General Information

The packaging must be opened carefully to prevent accessories from falling. Microscopes are sensitive precision instruments and must be handled with great care. Avoid abrupt movements during operation or transportation to protect optical components. Keep lens surfaces free from dirt and fingerprints, as these can impair image sharpness. Do not disassemble the microscope; leave optical components as they are.

Basic Information and Safety

General Information on Warnings

The following signal words are used to indicate potential hazards:

• DANGER: Indicates immediate danger that will lead to serious injury, permanent impairment, or death.
• WARNING: Indicates a potentially hazardous situation that may result in serious injury or death.
• CAUTION: Indicates a potentially hazardous situation that may result in minor injuries or property damage.
• NOTE: Indicates important information for handling or operation.

Warning symbols indicate the type of danger:

• General Hazard/Danger Point: ⚠️
• Electrical Voltage: ⚡️
• Optical Radiation: ☢️
• Electrostatic Sensitive Devices: ⚠️
• Flammable Substances: ?
• Explosive Substances: ?
• Commandment Sign (Prescribed Action): ℹ️

Intended Use

The OBT-1 and OBT-2 microscopes are intended for analyzing translucent, thin, high-contrast, and less demanding specimens, such as plant tissue, stained cells, and parasites.

Improper Use

Do not use the device in potentially explosive atmospheres, with liquids, or on live parts. Unauthorized structural changes, additions, or conversions are prohibited.

Warranty

The guarantee expires in case of:

• Non-compliance with specifications in the operating instructions.
• Use outside described applications.
• Changing or opening the device.
• Mechanical damage or damage from media, liquids, natural wear and tear.
• Improper set-up or electrical installation.
• Improper assembly or electrical installation.

Safety Instructions

Observe Operating Instructions

Read operating instructions carefully before commissioning or using the device, even with prior experience with KERN devices. Keep instructions accessible.

Staff Training

Only persons who have read and understood the operating instructions, especially the safety chapter, should use the appliance.

Security

• WARNING: Failure to observe safety information may result in electric shock, fire, or serious injury. Keep all safety information for future reference.
• Do not modify the device design, as this can lead to incorrect results or safety defects.
• Do not operate in potentially explosive or aggressive atmospheres.
• Do not immerse the appliance in water; ensure no liquids penetrate the interior. Use only in dry environments.
• Protect from direct sunlight and strong vibrations.
• Keep safety signs, stickers, and labels legible.
• Do not open the device.
• The lamp housing becomes hot during operation; avoid touching it.
• Risk of Injury due to Electric Shock: Prevent liquid penetration. Electrical work must be done by authorized specialists. Ensure the mains cable is not twisted or kinked. Use only the original adapter.
• Risk of Suffocation: Do not leave packaging material carelessly; it can be a toy for children. The appliance is not a toy.
• Electrostatic Sensitive Device: The device can be destroyed by electrostatic discharge. Handle sensitive components with care.
• Risk from Optical Radiation: Lamps generate intense optical radiation (UV, VIS, IR) that can cause skin and eye damage. Do not expose eyes or skin to radiation. Do not insert reflective objects into the beam path. Use protective equipment if necessary. Never look into the eyepieces when the beam path is open.
• Battery Hazards: Improper use of batteries can cause fire, explosion, or toxic fumes. Protect from heat, pressure, and liquids. Do not short-circuit contacts. Do not modify batteries or chargers. Never charge non-rechargeable batteries. Do not use defective batteries.

Transportation and Storage

Note

Improper storage or transport can damage the device. Follow the provided information.

Transportation

Use original packaging for shipping. Pack assembled and disassembled moving parts separately to prevent shock damage.

Storage

Avoid direct sunlight, extreme temperatures, shocks, dust, and high humidity. Recommended range: 0-40°C and up to 85% relative humidity. Place on a firm, smooth, horizontal surface. Cover with the dust cover when not in use to prevent dust damage to optics. Store accessories like lenses in a drying box with desiccant.

Packaging/Return Transportation

Returns are subject to general terms and conditions. Keep original packaging for returns. Disconnect cables and loose parts before shipping. Refit transportation locks and secure all parts.

Unpacking and Commissioning

Unpacking

Check the device, packaging, and parts for damage during transportation upon receipt. Notify KERN GmbH immediately if damage is found. For returns, follow the "Packaging/return transportation" instructions.

Initial Commissioning

Clean the microscope as described in chapter 9 before initial use to ensure proper function.

Assembly

Microscope Head

For OBT 101-106 models, the microscope head is pre-attached. Turn it to the front for use. If removing the head, avoid touching lenses with bare fingers and prevent dust entry.

For OBT 231, the ODC 231 microscope camera is in separate packaging. Attach it to the microscope using the provided opening and secure with the locking screw. Refer to the camera's operating instructions.

Lenses

Standard objectives are pre-screwed onto the nosepiece. Remove protective film before use. Objectives are arranged for increasing magnification when rotated clockwise. If removing objectives, handle with care to avoid touching lenses or allowing dust entry. Use immersion oil with low fluorescence for "OIL" marked objectives.

Eyepieces

For binocular devices, use eyepieces of the same magnification. They are usually fixed with a screw. Loosen the screw to remove them. Avoid touching lenses with bare fingers and prevent dust entry.

Condenser

The condenser is fixed below the stage. The aperture diaphragm lever points forward. The condenser height is adjustable but not centerable. Pressing the side lever moves it up or down. Avoid touching optical lenses.

Operation

First Steps

1. Connect the power supply.
2. Switch on the lighting and set the light intensity to a low level using the dimmer to protect your eyes.
3. Place a microscope slide with the specimen on the stage, cover glass facing up.
4. Secure the slide using the slide holder.
5. Move the slide manually or via adjustment wheels to the correct position in the beam path.

Focusing

(Pre-) Focusing

To achieve a sharp image, ensure the correct distance between the objective and the specimen. Start with the lowest magnification objective. Look through the right eyepiece with the right eye and slowly turn the coarse adjustment knob. Raise the stage until it is just under the objective, then slowly lower it until an image is recognizable. Use the fine adjustment knob for final sharpness.

Adjusting the Interpupillary Distance

For binocular viewing, adjust the distance between the eyepiece tubes by pulling them apart or pushing them together until the fields of view from both eyes completely overlap, forming a single circular image.

Diopter Compensation

Compensate for differences in visual acuity: Focus the image using the right eyepiece and coarse/fine drives. Then, look through the left eyepiece and adjust the diopter compensation ring on the left tube socket until the image is sharp for the left eye.

Magnification and Lighting

Setting the Magnification

After initial focusing, rotate the nosepiece to select the desired magnification objective. Ensure the objective is properly locked and clears the object holder. Check from the side to ensure sufficient clearance.

Setting the Lighting

Optimize light guidance for clear images. The height-adjustable condenser with aperture diaphragm is key. For initial settings, use the lowest magnification. Adjust condenser height for contrast. Refine with the aperture diaphragm lever: nearly fully right for low magnification (small opening), move left for higher magnification (larger opening). The visible aperture diaphragm should be about 2/3 of the pupil diameter. Adjust brightness using the dimmer, not the aperture diaphragm.

Advanced Operation

Use of Oil Immersion Lenses

For 100x objectives labeled "OIL", apply a drop of immersion oil to the cover slip (0.17 mm thickness). Lower the stage, bring the 100x objective into the beam path, and slowly raise the stage until light contact is made. Do not press the specimen and lens together. Clean components that contacted oil after use.

Maintenance and Power

Changing the Bulb (LED)

Switch off and unplug the device. Unscrew the field lens housing. The LED can be pulled out of its socket. Ensure correct polarity when mounting a new LED.

Use of Batteries

Open the battery compartment on the bottom of the microscope. Insert 3x 1.5V AA batteries. Battery operation is only possible when the power plug is removed.

Troubleshooting

Refer to the table below for common issues and their possible causes:

Service

If you have questions or encounter problems, contact your specialist dealer. The device should only be opened by trained KERN service technicians.

Power Supply and Battery Operation

Mains Connection

WARNING: Connect only if the microscope's mains voltage information matches the local voltage. Important: Check the mains cable for damage. Ensure the power supply unit does not contact liquids. The mains plug must remain accessible.

Risk of Fire and Explosion: Observe battery safety information. Never recharge non-rechargeable batteries.

Operation Modes: The microscope can operate via mains adapter or 3x 1.5V AA batteries.

Maintenance, Servicing, and Disposal

Cleaning

Keep the appliance clean and dust-free. Switch off power before cleaning wet surfaces. Use a lint-free cloth for glass components. For oil stains, use a lint-free cloth moistened with an ether/alcohol (70/30) mixture. Handle chemicals with care in well-ventilated areas. Avoid organic solutions on painted surfaces; use a neutral cleaner. Other cleaning agents include special lens cleaner, optical cloths, bellows, and brushes. Regular maintenance ensures longevity.

Maintenance and Repair

Do not modify the device or install unauthorized spare parts. Contact the manufacturer for repairs.

Waste Disposal

WARNING: Old appliances and accessories must not be disposed of with household waste. Dispose of packaging and the device according to national/regional legislation. The device contains electronic components, plastic, and metal. Improper disposal harms people and the environment. Proper disposal recovers raw materials.

Battery Disposal: Rechargeable batteries and batteries do not belong in household waste. Dispose of them according to applicable national or regional laws.

Battery Law Information

Note in accordance with the Battery Act - BattG (Germany): End users are legally obliged to return used batteries and rechargeable batteries. They can be returned free of charge to municipal collection points or retailers. Batteries containing harmful substances are marked with a crossed-out waste bin and chemical symbols (Cd, Hg, Pb).

Further Information

Illustrations may differ slightly from the product. Descriptions and illustrations are subject to change without notice. All language versions are non-binding translations; the original German document is binding.