Focusing and alignment method of tool microscope
When using a tool microscope, accurate focusing and aiming, the error of the measurement results of the same object under test is generally within the range of 1-2 microns, so only correct focusing and aiming can ensure the accuracy of the measurement results. The correct method of focusing and alignment (crimping) is introduced as follows:
1. Focusing method
1. First adjust the eyepiece diopter, that is, first adjust the eyepiece diopter to observe a clear reticle image in the eyepiece field of view. If the measurer cannot get a clear reticle image in the eyepiece field of view, the eyepiece diopter should be adjusted Circle, so that the diopter is adapted to the visual acuity of the measurer, so that a clear meter-shaped line can be obtained.
2. Move the central microscope through the focusing handwheel to get a clear image of the object outline in the field of view of the eyepiece, and then move the vertical and horizontal worktables for alignment. If the measurer's eyes shake the eyepiece up and down, left and right, and there is no relative movement between the object image and the cross-shaped line in the field of view, it means that the measured part is correctly imaged on the cross-shaped line reticle, and the measurement can be carried out at this time. If there is relative movement between the object image and the cross-shaped line, it means that the microscope is not focused well, and further careful focusing is required to make the object image and the cross-line reticle on the same plane.
2. Alignment (crimping) method
Alignment (pressing line) is to overlap the edge of the image outline of the measured piece with the cross-shaped line, that is, the so-called aiming. For a specific tool microscope, the accuracy of the instrument is certain, and the measurement accuracy must be compared. High and reliable, to a large extent depends on the correct alignment method, there are two alignment methods, one is the gap alignment method, the other is the overlapping alignment method.
1. Gap alignment method, the gap alignment method is suitable for angle measurement. When measuring the angle, when any dotted line of the rice word line is placed close to one side of the measured angle in the field of view, a narrow gap is maintained between the dotted line of the rice word line and the edge of the measured angle, and the measurer uses this gap The uniformity of the size is used to judge the degree of alignment between the dotted line of the rice line and the edge of the image under test. If the above-mentioned alignment method is not used, but the method of directly overlapping with the edge of the image is used, it will not only make it difficult for the measurer to align, but also increase the measurement error. At this time, because the image of the outline of the tested part in the field of view is not a thin line, but a light and dark outline, and the engraved line of the meter line has a certain width. If they are overlapped and measured, a large alignment error is bound to occur, especially when the side of the measured angle is relatively short, this situation is even more serious. Therefore, the gap alignment method should be used in angle measurement.
2. Overlap alignment method, if the above-mentioned gap alignment method is still used in length measurement, the length measurement error will increase. The reason is that the gap cannot be measured but is included in the value of the measured length. Therefore, the overlapping alignment method is used in length measurement. It is to overlap the dotted line of the rice character line with the edge of the outline image, so that half of the dotted line is inside the outline image and the other half is outside the image. When aligning the line, the center of the dotted line of the meter line should be used as the standard, and the extended part can be used as a reference to obtain accurate measurement results.
