Three Precautions for Operating a Universal Tool Microscope
1. Pay attention to the focusing sequence of the eyepiece and objective lens
Many people use an objective lens to focus at the beginning of the measurement. After adjusting the focal length of the object, they use the "meter" line in the eyepiece to align and measure. If the "meter" line is not clear enough, the eyepiece will be focused. In fact, this order is incorrect because it can cause some ghosting in the image of the object being measured after being focused earlier. The correct method is to first adjust the "meter" line in the eyepiece clearly, and then focus on the object, so as to ensure that the "meter" line and the image of the object are clear.
2. Pay attention to burrs and scratches on the surface of the tested part before measurement
During the processing, use, and transportation of the test piece, some burrs and scratches may occur, which are not easy to detect. However, these defects can easily cause alignment errors of the universal tool microscope or result in the measurement surface not being on the same focal plane, forming certain local shadows and affecting the accuracy of the measurement results. Therefore, it is necessary to thoroughly remove these surface burrs and scratches.
3. Pay attention to installing the tested component correctly
There are generally two installation forms for the test piece on a universal tool microscope: (1) placement of flat test pieces. For flat measuring parts, it is important to note that the measured surface of the part should be on the same focal plane, otherwise it is easy to form local shadows. For parts with chamfers on the measured surface, it is better to make the chamfer face downwards, otherwise it may cause unclear focusing and inaccurate measurement. (2) Installation of axis measuring components. Axial measuring components generally rely on the central hole for positioning. Before installation, the hole must be cleaned thoroughly, especially to eliminate sediment and burrs, otherwise it will cause the axis of the measured component to be different from the center line of the instrument, resulting in significant measurement errors. This situation is often encountered in daily measurements. A good solution is to check the runout error of the outer diameter of the measured shaft with the horizontal line of the "meter" line in the instrument dividing board after installation, in order to determine whether the measured part is installed correctly.
