Microscope Parts And Function

November 2, 2021

The main parts of the optical microscope are the foot, tube, nosepiece, column, stage, carriage, coarse and fine screw, eyepieces, objective, condenser, diaphragm and transformer.

The light microscope is an optical lens-based microscope that is also known by the name of light microscope or bright field microscope. It can be monocular or binocular, which means that it can be looked at with one or two eyes.

Mechanic system

Base or foot:  It is the piece that is in the lower part of the microscope and on which the rest of the elements are mounted. It tends to be the heaviest part to provide enough balance and stability under the microscope. It is common to include some rubber stops to prevent the microscope from sliding on the surface where it is located.

Arm:  The arm constitutes the skeleton of the microscope. It is the middle piece of the microscope that connects all its parts. It mainly connects the surface where the sample is placed with the eyepiece where it can be observed. Both the objective and eyepiece lenses are also connected to the telescope arm.

Stage:  This is the surface where the sample to be observed is placed. Its vertical position relative to the objective lens can be adjusted by two screws to generate a focused image. The stage has a hole in the center through which the specimen is illuminated. Generally, there are two clamps attached to the stage that allow the sample to be held in a fixed position.

Tweezers:  The tweezers have the function of keeping the preparation fixed once it has been placed on the stage.

Coarse screw: This screw allows you to quickly  adjust the vertical position of the sample relative to the objective. It is used to obtain a first focus that is adjusted later by means of the micrometer screw.

Micrometer screw:  The micrometer screw is used to achieve a more precise focus on the sample. Using this screw, the vertical displacement of the stage is adjusted slowly and with great precision.

Revolver:  The revolver is a rotating part where objectives are mounted. Each objective has provides a different magnification, the revolver allows to select the most suitable for each application. Usually the revolver allows you to choose between three or four different objectives.

Tube:  The tube is a structural piece attached to the telescope arm that connects the eyepiece to the objectives. It is an essential element to maintain a correct alignment between the optical elements.

Optical system

Spotlight or light source:  This is an essential element that generates a beam of light directed towards the sample. In some cases the light beam is first directed towards a mirror which in turn deflects it towards the sample. The position of the focus in the microscope depends on whether it is a transmitted light or a reflected light microscope.

Condenser:  The condenser is the element in charge of concentrating the light rays coming from the focus to the sample. In general, the light rays coming from the focus are divergent. The condenser consists of a series of lenses that change the direction of these rays so that they become parallel or even convergent.

Diaphragm:  The diaphragm is a piece that allows regulating the amount of light incident to the sample. It is usually located just below the platen. By regulating the incident light it is possible to vary the contrast with which the sample is observed. The optimum point of the diaphragm depends on the type of sample observed and its transparency.

Objective:  The objective is the set of lenses that are closest to the sample and that produce the first stage of magnification. The lens usually has a very short focal length. In modern microscopes, different objectives are mounted on the turret. This allows you to select the appropriate lens for the desired magnification. The magnification of the objective along with its numerical aperture is usually written on its side.

Eyepiece:  This is the optical element that provides the second stage of image magnification. The eyepiece enlarges the image that has been previously magnified by the objective. In general, the magnification provided by the eyepiece is less than that of the objective. It is through the eyepiece that the user observes the sample. Depending on the number of eyepieces, it is possible to distinguish between monocular, binocular and even trinocular microscopes. The combination of objective and eyepiece determines the total magnification of the microscope.

Optical prism:  Some microscopes also include prisms inside to correct the direction of light. For example, this is essential in the case of binocular microscopes, where a prism splits the beam of light coming from the objective to direct it towards two different eyepieces.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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