You certainly know the microscope, right? Yes, this tool is used to see small objects that are invisible to the naked human eye. And the electric microscope is one of the types of microscopes.
A microscope is an instrument used to see small objects that are invisible to the naked eye. The term microscope itself comes from the Greek, namely micros which means 'small' and sophos which means 'goal'. So, a microscope aims to see small objects.
The microscope was first invented in 1590 by an optometrist named Zacharias Janssen and assisted by Hans Janssen. They made the first microscope, which was able to see objects up to 150 times their original size.
This discovery led to other discoveries in the field of microscopy. In 1609, Galileo made a microscope using an optical lens called an optical microscope. This tool only has the ability to see objects at a size of 200 nanometers.
Not until there, a Dutchman, Antony Van Leeuwenhoek (1632-1723) then developed a magnification microscope. The developed microscope is capable of magnifying objects up to 200-300 times their original size.
With his development tools, he had many small objects and discovered the existence of very small animals known as protozoa.
He also found many observations including the shape of rods, cocci and spirals which are now known as bacteria. His observations contributed to the birth of a new science, namely microbiology, the science that studies very small life.
After that, the invention and development of the microscope continued. The shortcomings of the previous microscope were overcome so that the light microscope was finally found. Light microscopes can magnify objects up to 1,000 times and the human eye can see two objects that are about 0.0002 mm apart.
To increase the magnification ability of objects in light microscopes, the use of light with blue or ultraviolet light which has a short wavelength can be applied. In addition, object magnification can be circumvented by utilizing several substances that have a high refractive index such as oil which can increase the resolution to above 100 nanometers. But this also has not satisfied scientists.
There are many smaller objects that cannot be seen using a light microscope. Developments are continuing.
In 1920 discovered the phenomenon of electrons. This discovery led to the discovery of the electron microscope, which is a microscope that uses electron beams, the wavelength of electrons is shorter than light.
In 1932 the electron microscope was developed. This microscope has the ability to magnify small objects up to 2 million times their original size.
The invention of the electron microscope led to other discoveries in the field of microbiology such as the discovery of bacteria, cells, and finally viruses.
Electric Microscope
An electric microscope (compound light microscope) is a light microscope that uses electric light. In conventional microscopes, light comes from sunlight. Light is reflected through a plane mirror or a concave mirror which is below the condenser. The light from outside is directed by the mirror into the condenser.
A light microscope is an optical microscope. Called a light microscope because it uses light to produce images and uses an optical lens consisting of three lenses. This microscope has various types, ranging from simple to complex microscopes.
Parts and Functions of the Light
Microscope The light microscope consists of parts, each of which has a specific function to support the process of good observation. There are two main parts, namely:
1. Optical section
This section consists of the objective lens, eyepiece lens, and condenser.
Here's the explanation:
Objective lens: this lens serves to form the first image and determine the tiny parts that will be visible in the final image. And serves to enlarge the shadow of the object. The magnification capability of this lens is in the range of 4 to 100 times. In the microscope usually found three to four objective lenses.
Ocular lens: the ocular lens is located at the top end of the tube adjacent to the observer's eye. This lens serves to enlarge the image that has been produced by the objective lens. Its magnification ability ranges from 4 to 25 times.
Condenser: a lens that serves to support the lighting on the object to be observed. With the right settings, the separation will be obtained clearly. The condenser is made of converging.
2. Non-optical parts
This section consists of:
Microscope tube: microscope tube serves to connect the objective lens and eyepiece lens and functions in adjusting the focus of the lens.
Microscope foot: serves to support the microscope so that the microscope is balanced so that the observation process goes well.
Microscope arm: serves as a hand support for the convenience of the observation process.
Diaphragm: functions to regulate incoming light.
Object table: serves as a place to put the object to be observed.
Revolver: functions in adjusting the magnification of the objective lens. How it works by turning the revolver.
Fine dial (micrometer): serves to raise and lower the microscope with slow motion so that the object to be observed is not missed.
Coarse dial (macrometer): serves to raise and lower the microscope in a fast way.
Glass clamp: serves to clamp the glass so it is not easily shifted. The clamped glass is the glass that coats the object of observation. This glass is called object glass.
Angle adjuster (inclination): serves to straighten the microscope and adjust the angle of the microscope.
Lighting device: this section is located under the table, consists of a plane mirror and a concave mirror. Serves to explain and reflect light to objects.
How to Use an Electric Microscope
After knowing the functions and parts of a microscope, it is also necessary to understand how to use this magnifying tool in observing activities. The following are the steps for using a microscope:
Take the microscope carefully, by holding the arm of the microscope. Then place it on a flat table. Avoid touching the lens. If the lens part of the microscope looks dirty, clean it carefully and gently using lens paper (can be purchased at a camera/photo shop). As for the non-optic parts, they can be cleaned with a clean flannel.
Rotate the revolver to adjust the magnification of the objective lens, with the objective lens positioned one axis with the eyepiece.
Adjust the mirror and diaphragm to determine the strength of the incoming light. The results of the lighting can be seen from the ocular lens which looks bright in a round shape.
Place the preparation on the object table right at the preparation hole. To keep it from shifting, clamp it with object clamps.
Adjust the focus by turning the coarse dial (macrometer) so that the object is clearly visible. Then son fine dial (micrometer) to sharpen the object. This setting is done by looking at the object from the eyepiece.
If the image of the object is visible, then to enlarge the object, replace the objective lens with a size of 10 times, 40 or 100 times. Replacement is done by turning the revolver until you hear a click.
When the observation using a microscope has been completed, store it in a safe place and not damp. A microscope that is placed in a humid area can cause the lens to mold and this makes it difficult to see the object you want to study. And don't forget to clean from things that contaminate the microscope.