The structure and operation of metallographic microscope
There are many types and models of metallographic microscopes, with the most common being desktop, vertical, and horizontal. Metallographic microscopes usually consist of three main parts: optical system, illumination system, and mechanical system. Some microscopes are also equipped with photography devices. Now let's introduce the functions of each part of the metallographic microscope.
Stage: Used to place metallographic specimens. There are guide rails between the stage and the lower tray, which can be manually pushed to make a certain range of cross directional movements on the horizontal plane to change the observation position of the specimen.
Aperture light bar and field of view light bar: The aperture light bar is installed on the illumination reflector base, and adjusting the aperture light bar can control the thickness of the incident beam to ensure that the object image reaches a clear level. The field of view light bar is located under the objective lens holder, and its function is to control the field of view, making the field of view in the objective lens bright and shadow free. There are also two adjustment screws on the ring engraved with straight lines, used to adjust the center of the light bar.
Objective lens converter: The converter is spherical in shape and has three screws on it. It can be used to install objectives with different magnifications. By rotating the converter, each objective lens can enter the optical path and be used in combination with different eyepieces to obtain various magnifications.
Eyepiece tube: The eyepiece tube is installed at a 45 degree angle on a hemispherical base with a prism, and can also be turned 90 degrees horizontally to cooperate with the camera for metallographic photography.
Metallographic microscope is a precision optical instrument that requires careful and cautious use. Before using a microscope for work, it is necessary to familiarize oneself with its structural features and the mutual positions and interactions of its main components, and then operate according to the microscope's operating procedures.
Instructions for using metallographic microscope:
1. Firstly, plug the light source plug of the microscope into the transformer and connect the power supply through a low-voltage (6-8V) transformer.
2. Select the required objective lens and eyepiece according to the magnification, install them on the objective lens holder and eyepiece tube respectively, and rotate the converter to a fixed position.
3. Place the sample in the center of the sample table, with the observation surface facing downwards and press it down with a bullet.
4. Rotate the coarse adjustment handwheel first to lower the stage, while observing with the eyes to make the objective lens as close to the surface of the sample as possible (but not touching), then rotate the coarse adjustment handwheel in the opposite direction to gradually raise the stage to adjust the focal length. When the field of view brightness increases, use the fine adjustment handwheel to adjust until the object image becomes clearer.
5. Adjust the aperture light bar and field of view light bar appropriately to obtain the best quality object image.
