Eyepiece structure of metallographic microscope
The structure of the head is relatively simple, but there are many types. The four eyepieces of the xJ-16 metallographic microscope are all Huygens type, with magnifications of 6x, 10x, and 15x, and their structures are roughly the same (as shown in Figures 3-ll and 3-12).
(1) Huygens eyepiece structure
The 6×, 10× and 15× eyepieces are all composed of two plano-convex lenses with the convex side facing downward: the upper plano-convex lens has a smaller outer diameter and is the lens closer to the eye when observing, so it is called an eyepiece. Inside the eyepiece holder 5. The cylindrical surface of the lower end of the eyepiece holder 5 is threaded so as to be screwed into the upper end of the sunscope barrel 4 . The lower plano-convex lens has a larger outer diameter, and the light from the objective lens is imaged near the central circular hole of the diaphragm 3 through it, which is called a field lens. It is also fixed in the field lens holder 1 by the wrapping method, and is connected to the lower end of the eyepiece tube 4 by threads. The structure of the Huygens eyepiece is relatively simple, and the positions of the two lenses have been determined by the length of the eyepiece. Therefore, the eyepiece or field lens can be disassembled when necessary (for example, to eliminate stains on the lens surface). No special adjustments are required during assembly and restoration to achieve the original accuracy.
(2) 10x reticle metallographic microscope eyepiece structure
The 10x reticle eyepiece is formed by placing a circular glass piece (cross reticle) engraved with cross lines and reticle scales at the position of the eyepiece diaphragm (due to 3d13). Observed from the eyepiece, the cross mark to the ruler just reflects on the object image. Therefore, it can be used to conduct rough quantitative analysis of the metallographic structure, such as determining the depth of the carburized layer, the grain size of the material, etc. The difference between the 10x reticle eyepiece structure and the 10x reticle eyepiece structure is that the 10 M reticle eyepiece has a cross reticle 3 at the diaphragm, and the eyepiece holder 5 should not be screwed on the eyepiece tube, but through a thread Connected to the reticle base 8. The reticle base 89U is rotated at the upper end of the eyepiece tube 4. By turning the eyepiece holder 5, the distance between the eyepiece and the reticle can be adjusted, so that observers with different visual acuity can obtain the clearest image of the scale line.
