Microscope Parts | A Guide on their Location and Function
Microscope parts here we see are of a compound microscope.
Simple microscopes have just a lens, stage and a light source.
But compound microscope has many parts and also is widely used in the laboratory.
It majorly consists of parts which assist in viewing with a naked eye, a magnifying lens, light source and a stage to hold the sample.
But besides there also many parts meant to adjust a provide a fine resolution of the microscopic objects.
There are almost 15 parts in a microscope. But they can be divided based on their purpose in the instrument like
A) Parts which assist in viewing the object B) Part which helps in adjustment for clear view c) Part which provides sufficient light to the object to be seen D) Support tine parts which help to hold the sample and others.
But we will see them based on their location from top to bottom of compound microscope.
3. Revolving nosepiece
4. Objective lens (Three 10x , 45x, 100x)
5. Coarse adjustment
6. Fine adjustment
8. Rack stop
11. Side-ward movement knob
12. Front and back movement knob
13. Condenser and Diaphragm
14. Mirror (convex and concave mirror)
1. Eyepiece: This is the first part which you come across when viewing object in the microscope from the top. It is a transparent glass lens which enables to see the object clearly. This eyepiece can be removed and put back into the tube column. It has two glass lens one at the top which is just flat while the other towards the object is slightly convex to the bottom. One can remove the eyepiece and wipe it with a cloth to free it of any dust particles.
2. Tube: It is a long columnar shaped tube which holds eyepiece and also the nosepiece including the objective lens. It holds the nose piece immediate to the end to which objective lenses are fixed. It has rulings which helps to move it up an down to get a clear view of the object.
3. Revolving nosepiece: It is a circular metallic piece holding the magnifying lenses to the tube. It is revolves freely so as to select the required lenses needed to focus.
4. Objective lens: These are the lenses which help to magnify the objects on the slide placed on the stage. The resolution most common are 10x, 45x and 100x with 10x having the lowest magnification power and 100x having the highest magnification power. These three eyepieces can be removed and replaced if required.
5. Coarse adjustment: This is a adjustment knob present at the junction of arm and the tube. It has larger knob than the lower one. It is routinely used for rough adjustment. One need to use it to adjust the eyepiece till it reaches the slide but not touch it. From there, fine adjustment can be used to get clear resolution.
6. Fine adjustment: This is smaller and circular know seen below the coarse adjustment knob. It is fixed to the arm of microscope. It helps to adjust the magnification lens to the correct height for better resolution. Its movement is slow and very fine. This know is essential besides the coarse adjustment know to for easy and precise focus. Also the chances of damage to the sample slide on the stage is also eliminated due to this knob.
7. Arm: It holds the eyepiece, objective lens, stage, light source in a straight line. It is also useful to carry the microscope from one place to another.
8. Rack stop: This is small threaded pin which helps to fix the column tube at particular height after being adjusted to desired height by the adjustment knobs. Once the adjustment of height is done, the rack stop is tightened to hold the tube at the set height. To further decrease or increase the height, the rock stop has to be loosened.
9. Stage: It is the place where slide containing the test sample is placed for evaluation. It is a square shaped metallic plank consisting of clips, sidewise adjustment and forward adjustment knobs. Stage is always kept clean during and before start of experimentation. The stage has a an orifice through which light from the mirror falls in the slide. This light helps in visualization of the microscopic sample.
10. Clips: These are two in number and help in fixing of the slide in a fixed spot on the stage.
11. Side-ward movement knob: This know is located over the stage and helps to move the slide to left or right directions.
12. Front and back movement knob: This is another knob which is also situated on the stage and control forward and backward movements of the slide.
13. Condenser & Diaphragm: Condenser is located below the stage and helps to gather light from mirror and condense it on to the stage. Diaphragm is a closure which helps to close the aperture below the stage through which light from source falls on to it. For low light intensity, diaphragm is closed while for more intensity is kept wide open.
14. Mirror (convex and concave mirror): This is fixed to the base below the diaphragm. It passes light on to the stage.
15. Base: This is the foot of the microscope over which entire weight of the instrument rests. It is heavy and flat linked to the arm.