Principles of Microscope Reading
A length measuring tool that uses a microscope optical system to magnify, subdivide and read the graduations of the linear scale. It is often used as a reading part of a ratio meter, a length measuring machine and a tool microscope, or as a positioning part of a jig boring machine and a jig grinding machine, etc. It can also be used alone to measure smaller dimensions, such as thread spacing, hardness testing Indentation diameter, crack and hole diameter, etc. Its division value has several kinds of 10 microns, 1 micron and 0.5 microns.
According to different subdivision principles, reading microscopes are usually divided into three types: direct reading type, reticle moving type and image moving type.
1. Direct-reading reading microscope: the scale on the line ruler is partially enlarged by the objective lens and then imaged on the reticle. If the line spacing is 1 mm, it is enlarged to the same distance as the 100 graduations on the reticle. Through the eyepiece (magnification) the graduation value of 0.01 mm can be read.
2. Marking mobile reading microscope: Turn the micro handwheel during measurement to align the double engraved line on the movable reticle with the line pattern of the line ruler, and read the percentile from the reading drum or other reading mechanism Numbers and thousandths, tenths are read from the movable reticle. In order to avoid the wear of the precision thread (or other micro-motion mechanisms) on the micro-handwheel, some microscopes make the double engraved lines on the movable reticle into double Archimedes spirals (c in the figure). The pitch of the double Archimedes spiral is equal to 1/10 of the thread ruler and the thread pitch multiplied by the magnification of the objective lens, and 100 equal divisions are engraved on its inner circle, so after it is aligned with the thread image, The tenths can be read from the fixed reticle, and the percentile and thousandths can be read from the movable reticle.
3. Image mobile reading microscope: add movable optical elements (such as plane parallel glass, optical wedge glass or compensation lens, etc.) between the objective lens and the reticle. When this type of optical element is moved, the line image of the line ruler will move, and after the line image is aligned with the double reticle on the fixed reticle, the fixed reticle and the movable reticle can be read from the fixed reticle and the movable reticle respectively. Read out the tenths, hundredths and thousandths.
The component that magnifies the line scale scale through the objective lens and projects it on the video screen, and uses the reticle and micro-movement device to subdivide and read is called the optical reading head. It can reduce the fatigue of the human eye when aiming and reading, and its graduation values are 10 microns, 2 microns and 1 micron.
