Parts of a Compound Light Microscope

A compound light microscope gives us a view at a smaller world.

Making the minute gigantic, the compound light microscope is one of the primary tools for any scientist doing research. It is a high quality instrument with many parts, each with a specific function.

Eyepiece Objectives and Nosepiece

Eyepiece objectives each give a closer view of the specimen.

The most common eyepiece objectives found on the microscope of this type have a magnification of 4X, 10X, and 40X. Each one gives a greater amount of magnification to bring the specimen into view. You begin with the smallest one, 4X, and then can rotate the eyepieces around until you arrive at the highest of 40X. The nosepiece is found right above the objectives and is their support. It also turns manually, allowing the user to move from one level of magnification to the next. Supporting these and other parts of the microscope is the arm, which is the curved or bent section on the main body of the microscope.

Coarse and Fine Adjustment Knobs

The coarse and fine adjustment knobs help to bring clarity to the specimen.

The coarse adjustment knob raises and lowers the main body of the microscope. Raising or lowering the body tube, it helps to bring the slide into view. The fine adjustment knob, when slowly turned, brings even greater clarity to the specimen. When switching between levels of magnification, use this knob to fine tune the image.

Body Tube And Eyepiece

The body tube runs through the main structure of the microscope from the eyepiece and down to the objective lenses. The eyepiece at the very top is the point of contact for the eye to view the specimen through. The body tube must be adjusted slowly to prevent the objective lenses from striking the slide and breaking it.

Stage And Aperture

The stage on a compound light microscope is the platform where the slide specimen is set so that it can be viewed. On the stage are two movable metal strips called the stage clips that hold the slide in place during viewing. These can be gently pulled upward and then slid over the top of the slide for a secure positioning. Below the slide is a small hole called the aperture, which allows light to enter from below. This gives sufficient illumination for the viewer to be able to see the specimen.

Base, Power Switch, Light Source

At the bottom, the light source provides the necessary illumination that is focused up through the aperture for viewing. Also near the bottom of most microscopes you will find the power switch, which controls the electrical flow. The base is the final piece of the microscope and supports the entire setup. It is normally wider than the top and weighted so that the microscope will stay steady while work is done.

Considerations

A compound light microscope is made sturdy and to last, but requires care. You should be knowledgeable about the parts, their function and proper maintenance. If used improperly, parts can be damaged and in some cases very expensive to replace. When you move the microscope, one hand should be put under the base and the other holding the arm. This provides steady support and protection to move the microscope back to its storage area, and it should be covered to prevent dust from getting into the smaller parts. With proper care, knowledge and use a compound light microscope is a wonderful tool for taking in a smaller world.

References

• Miami University; The Compound Light Microscpe