The 14 Parts Of The Microscope, And Their Functions
The microscope has been a fundamental tool in research, especially in disciplines related to medicine and biology, such as microbiology, histology and cytology.
However, and despite its relative ease of use, this device has several parts which have different functions that, together, allow something microscopic to be seen by the human eye.
Next we will know the parts of the microscope in addition to detailing what role they play both structurally and in obtaining the image.
These are the parts that make up the microscope, which can be divided into two systems: the mechanical and the optical.
Mechanic system
The mechanical system of the microscope It includes all those parts that are part of the structure of the device itself
These parts provide balance, unite the parts that make up the optical system of the microscope and regulate both the sharpness and magnification of the image of the sample.
1. Base or foot
The foot constitutes the base of the microscope, being in the lowest part of the device and giving it support. It is usually the heaviest part of the entire microscope and it is thanks to this that the device achieves sufficient balance to avoid lying down.
This structure can have various shapes, but the most common is Y-shaped or rectangle. It usually includes a rubber stop to prevent it from sliding across the surface while in use.
2. Arm or spine
The arm, also called the column or handle, is the skeleton of the microscope. It is a piece that is located in the middle part of the device, connecting all its parts. This way, connects the surface where the sample to be observed will be placed and the eyepiece part through which it will be observed.
Both the lenses that make up the eyepiece and those found in the objectives are on the arm of the microscope.
The stage is the part on which the sample to be observed is placed. Is about a flat surface on which the glass strip containing the tiny object to be observed is placed To hold this glass strip, the plate has two metal clips.
The vertical position of the stage with respect to the objective lenses is adjustable using two screws, also allowing the degree of focus of the sample image to be modulated. In the center of the stage there is a hole through which the light beam from the illumination source, located at the base of the microscope, passes.
4. Coarse screw
The macrometric screw allows you to adjust the vertical position of the sample with respect to the objective. This screw, when turned, causes the microscope tube to slide vertically thanks to a system similar to that of a zipper.
Through this movement, it is possible to quickly focus the preparation on the stage.
5. Micrometric screw
The micrometric screw is a mechanism that used to achieve more precise focus of the sample to be observed. Although focusing with this screw is slower, it is more precise than with the coarse screw.
Thus, through this part of the microscope, it is possible to obtain a sharp focus by moving the stage vertically and almost imperceptibly. These movements are of the order of 0.001 millimeters.
6. Revolver
The revolver is a rotating piece on which the objectives are mounted. Its name comes from the fact that, when used, it moves and sounds like the revolver of a gun.
By turning the revolver, The objectives pass through the axis of the tube and are positioned so that what is on the stage can be seen Each of the objectives that are screwed into this piece have a different magnification and, by turning the revolver, it is possible to choose the most appropriate objective for the sample to be observed.
7. Tube
The tube is a structural piece, which is attached to the arm of the microscope, connecting the eyepiece to the objectives. This part It is what maintains the correct alignment between the lenses that make up the first and second phases of increasing the image of the sample.
The telescope’s optical system includes all the necessary elements to be able to enlarge the image of what is on the stage and correct its lighting All parts of the optical system are designed in such a way that it is possible to correct chromatic irregularities, such as light splitting into different colors.
1. Focus or light source
The spotlight, which provides illumination to the plate, It is usually made up of a halogen lamp which is located at the base of the microscope. The light leaves the bulb and passes into a reflector, sending the light rays to the stage.
Depending on the size of the microscope, this light source will have a higher or lower voltage. In the microscopes most used in laboratories, the voltage is usually 12 volts.
2. Capacitor
The condenser consists of a system of converging lenses that They capture the beam of light and concentrate its rays so that greater or lesser contrast is offered
Normally, the rays emitted by the light source are divergent. Using the condenser, it is possible to make these rays parallel or even convergent.
In the microscope there is a screw that is used to regulate light condensation This screw may be found in a different location depending on the model of the device.
3. Diaphragm or iris
The diaphragm is located above the light reflector and below the stage.
Through this part it is possible to regulate the intensity of the light, opening or closing the diaphragm, just like the human iris does when exposed to light coming from outside. The optimal point of the diaphragm will vary depending on the sample on the stage and the degree of illumination of the place where the microscope is located.
The objectives are the converging lenses that are regulated by the revolver. These lenses are what offer the first stage of magnification.
By turning the revolver clockwise, the objectives are coupled with each other allowing you to enlarge the image of what is being observed.
5. Eyepieces
Eyepieces are the lens systems closest to the observer’s eye. These are hollow cylinders that are located at the top of the microscope and have converging lenses.
These optical elements are what provide the second stage of image magnification. That is to say, first the image is magnified by the objectives and then magnified again by the eyepieces
The combination between the objective used and the eyepieces is what determines the total magnification of what is observed on the stage. Depending on whether the microscope has a single eyepiece or two, we speak of monocular microscopes or binocular microscopes. There are also trinocular microscopes.
6. Optical prism
Some microscopes include optical prisms, which are located inside the device and serve to correct the direction of light.
The existence of this part is very necessary in binocular microscopes since using the prism it is possible to divide the light beam into two so that it reaches both eyepieces and obtains an appropriate two-dimensional image.
7. Transformer
The transformer is necessary to be able to plug the microscope into power since, normally, the power of the microscope bulb is usually below the power of the common electric current.
Some transformers have a potentiometer which is used to regulate the intensity of the light.
