There are many kinds of optical microscopes, except ordinary ones, mainly including:
(1) Dark-field microscope, a microscope with a dark-field condenser, makes the illumination beam not enter from the central part, but shoot at the specimen from the periphery.
(2) fluorescence microscope, which uses ultraviolet light as light source to make the irradiated object emit fluorescence. The electron microscope was first assembled in 193 1 by Noel and Har Roska in Berlin. This microscope uses high-speed electron beams instead of light beams. Because the wavelength of electron current is much shorter than that of light wave, the magnification of electron microscope can reach 800,000 times and the lowest resolution limit can reach 0.2 nm.5438+098.
■ Main uses
Microscopes are used to enlarge images of tiny objects. Generally used for biological, medical and microscopic particle observation.
(1) Use the movement of the micro stage to measure the length with the cross mark of the whole eyepiece.
(2) Measure the angle with the rotating stage and the cursor differential angle dial at the lower end of the eyepiece, so that one end of the measured angle is aligned with the reticle and coincides with it, and then the other end coincides with it.
(3) Check the pitch, middle diameter, outer diameter, tooth angle and tooth profile of the thread with standard.
(4) Check the grain condition on the metallographic surface.
(5) Check the machined surface of the workpiece.
(6) Check whether the size or outline of the tiny workpiece is consistent with the standard parts.