Intro: Operating Procedure Of Compound Light Microscope System in 10 Steps
Microscope is a tool that enables us to view things that are too small
to be seen with the naked eye.
The most common type of microscope used in school science
laboratories is the
compound light microscope. It uses a system of two or more lenses to
collect and focus
transmitted visible light through a specimen to the eye.
It is the
principle tool for the study of biology and is often referred to as bright field microscopy. Animal
cells, plant cells, protozoa and bacteria can be easily seen with a compound light microscope. The
typical compound light microscope is able to magnify from 40x to 1000x, increasing our ability
to see detail so that
objects as small as 0.2 micrometres (µm) or 200 nanometres (nm) can be
seen.
Compound light microscopes may be monocular (for viewing using only one eye) or
binocular (for viewing using both eyes).
Compound light microscopes from various manufacturers
may appear different but operate on similar principles. A microscope is a delicate
precision instrument and
care must always be used when using, transporting and maintaining it.
A typical school microscope has three magnifications: Scanning, Low and
High. Each objective and eyepiece (ocular lens) will have the magnification written on it.
Some microscopes will also have an oil immersion objective.
The total magnification is the ocular magnification multiplied by the
objective magnification.
See table below
Operating procedure
To Set up and use a compound light microscope obey the following rules to
achieve good result
1. Read and be familiar with the user manual for your model of
microscope.
2. Carry the microscope with two hands, one under the base and the
other gripping the arm or frame.
3. Gently place the microscope on a flat, level surface and plug into a
power source. Some microscopes have a built in light source but others have a mirror
to focus natural light or an external light source.
4. With a built-in light source, turn on the light source and adjust
the light setting so that it is not too bright by turning or sliding the
brightness adjustment knob on the base.
5. ‘If using an external light source directs the light via the mirror.
Rotate the low power objective into position. Remove the eyepiece, look down
the body tube and adjust the mirror and diaphragm setting so light is reflected
up the tube and a circle of evenly illuminated light is visible in the field of
view. Replace the eyepiece. Use the concave mirror side if the microscope has a
fixed condenser lens or the flat mirror side if the microscope has an
adjustable condenser’ 1.
6. The iris diaphragm is located just above the light source on the
bottom side of the stage.
Using the lever attached, you can increase or decrease the amount of
light reaching the test sample. Look through the eyepiece and adjust the sub-stage
iris diaphragm to allow sufficient comfortable light through.
7. Between the stage and the iris diaphragm is the condenser. The
condenser further aids in the focusing of the light onto the specimen. In some
microscopes it can be moved up and down. To begin with, position it close to
the stage. If you have a problem focusing your specimen then adjust the
position of the condenser.
8. Adjust the stage down as low as possible with the coarse focus knob.
9. Begin by viewing the specimen with the lowest power objective lens
in place and then increase to the higher power objective lenses.
10. Select the 4x scanning objective by rotating the nosepiece,
ensuring it clicks into place
The best of both worlds, CILIKA’s benchtop series is a digital microscope with a traditional body. It brings together the benefits of digitization, the comfort of ergonomic design, and the reliability and sturdiness of a traditional setup. With its adjustable variable angle feature, users can work for longer and continuous hours without occupational hazards.
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