Classification of Special Objective Lenses for Metallurgical Microscope
1, with correction ring objective (Correctioncollarobjective): in the middle of the objective lens is equipped with a ring mounted adjusting ring, when turning the adjusting ring, can be adjusted within the objective lens lens between the distance between the lens group, so as to correct by the coverslip thickness is not standard coverage caused by the difference. Adjustment ring on the scale can be from 0.11-.023, in the objective lens shell is also marked with this number, indicating that the coverglass can be corrected from 0.11-0.23mm thickness between the error.
2, with iridescent diaphragm objective (Irisdiaphragmobjective): in the upper part of the objective lens barrel equipped with iridescent diaphragm, the outer side can also be rotated to adjust the ring, rotating the size of the diaphragm aperture can be adjusted, this structure of the objective lens is an oil-immersed objective, its role is to detect the dark field of view when the background of the field of view is not dark enough, resulting in the reduction of microscopy quality. At this time, adjust the size of the diaphragm, so that the background becomes darker, so that the object to be examined more brightly, to enhance the effect of microscopy.
3, phase contrast objective (Phasecontrastobjective): this objective is used for phase contrast microscopy special objective, which is characterised by the focal plane of the objective lens is equipped with a phase plate.
4, no cover objective (Nocoverobjective): some of the objects being examined, the top can not be added with a coverslip, so that in the microscopic examination should be used without a cover objective, otherwise the image quality will be significantly reduced, especially in the high-magnification microscopy is more obvious. This objective lens is often engraved on the shell NC, at the same time in the position of the thickness of the coverslip without the word 0.17, but engraved with "0".
5, long working distance objective: the focal length of this objective is greater than the ordinary objective, it is designed to meet the liquid material (high temperature metallography), liquid crystal, tissue culture, suspension and other materials designed for microscopy.
