Common methods of measurement for general purpose tooling microscopes
1. Knife edge method and axis cutting method:
The knife edge method and the axial cut method are a comprehensive optical and mechanical method that mainly measure the axial cut surface of the thread. This method can also be used to measure cylindrical, conical and flat specimens because the adjustment error is extremely small and is not affected by external influences. For example: the edges are not smooth, chamfers cover them, etc. The condition for using this measurement method is that the test piece must have a smooth and straight measuring surface, and the measuring knife is held against the test piece by hand, and it contacts the test piece on the measuring plane. For round parts, this measuring plane is tangent to the axis of rotation, and the thin line parallel to the edge of the knife edge represents the axial section of the specimen. Align the fine line with the reference reticle of the angle measurement eyepiece. The edge of the unworn knife edge is in contact with the alignment axis passing through the crosshair in the field of view. The distance from the thin line to the edge of the knife edge does not need to be considered when measuring. Only when measuring with a worn knife edge, it is required to subtract from the value. The error of removing the knife edge. What needs to be noted here is that dust and liquid residue on the inspection surface will cause errors when the knife edge position is inspected based on the light gap. The maximum height of the backing plate and the instrument is set and cannot be adjusted incorrectly. It must be cleaned before use.
2. Shadow method:
The shadow method is a purely optical method that can quickly adjust the instrument to align the specimen profile and compare the shape. This measurement method requires the test piece to be placed in the bottom-up light path and within the clear range of the alignment microscope, so as to obtain a shadow image of the test piece. The image of a round workpiece is a silhouette shadow along the axial plane, while the shadow image of a flat specimen is determined by its edges. The reticle on the rotating eyepiece and angle measuring eyepiece are used to measure tangent to the shadow. When comparing the shape of the test piece with the self-drawn figure, you can use a projection device and binocular observation.
3. Reflection method:
The reflection method is also an optical contact method. The characteristic of the reflection method is that it can measure edges and marks, such as scribing, punching, etc. This method can also use the engraved pattern of the rotating eyepiece to compare shapes. Determine the measuring plane according to the clear plane of the microscope. This measuring method is mainly used for flat specimens. Use the angle measuring eyepiece when measuring scribe lines and punch holes, use the dual image eyepiece when measuring the edge of the hole, and use the rotating eyepiece when comparing shapes.
4. Micrometric lever method
The micrometric lever method is used for measuring surfaces that cannot be aligned with optical methods for measurement, such as holes, various curved surfaces and spiral surfaces. Special attention should be paid here that the diameter of the measuring head when touching or touching the curved surface in the opposite direction must also be included in the measurement. within the results. For special measurements it is recommended to make suitable contact rods yourself. A spherical measuring head with a certain diameter can be used to test the rolling curve, and a pointed measuring head can be used to test the spiral surface in a certain measuring plane. The knife-edge measuring head is used to measure the projection of cut planes and spatial curves with only two coordinate axes.
