1、 Vernier gauge
Vernier measuring tool is a measuring tool made by using the principle of the length difference between the ruler body and the vernier scribed line. Commonly used vernier gauges include vernier caliper, height vernier caliper, depth vernier caliper, tooth thickness vernier caliper and vernier universal angle ruler.
1. Vernier caliper: vernier caliper can be used to measure length, thickness, outer diameter, inner diameter, hole depth, center distance, etc. The accuracy of vernier caliper can be 0.1, 0.05 and 0.02mm. It is mainly composed of ruler body, vernier, internal measuring claw, external measuring claw, depth ruler and fastening screw.
2. Vernier universal angle ruler: vernier universal angle ruler is a measuring tool used to measure the internal and external angles of workpieces. The measurement accuracy is 2 points and 5 points, and the measurement range is 0-320 degrees.
2、 Micrometer
Micrometer is one of the most commonly used precision measuring tools in measurement. There are many kinds of micrometers, including outer micrometer, inner micrometer, depth micrometer, common normal micrometer, etc. according to their different uses. The measuring accuracy of micrometer is 0.01mm.
3、 Dial indicator
The dial indicator is an indicating gauge with a measurement accuracy of 0.01mm. When the measurement accuracy is 0.001mm or 0.005mm, it is called a dial indicator. The measuring range of the dial indicator refers to the maximum displacement of the measuring rod. There are three commonly used types: 0-3mm, 0-5mm and 0-10mm.
4、 90 degree ruler, knife edge ruler, feeler gauge
1. 90 degree ruler: this measuring tool is mainly used to detect the perpendicularity of adjacent surfaces of workpieces. The 90 degree angle ruler is composed of a ruler base and a ruler seedling. During measurement, make the inner or outer side of the ruler base close to the datum plane of the measured workpiece, and the inner or outer side of the ruler seedling close to the measured surface of the workpiece. Observe the size of the light transmission gap between them, and judge the perpendicularity error between the adjacent surfaces of the workpiece. During measurement, the 90 degree angle ruler cannot be tilted back and forth, left and right, and the ruler seat and ruler seedling cannot be inverted, so as not to affect the correctness of the test results.
2. Knife edge straight edge: the knife edge straight edge is used to detect the straightness and flatness of the workpiece plane. The accuracy of the straightness of the knife edge (edge) of the knife edge straight edge is very high, and the arc radius of the knife edge is 0.1-0.2mm. When inspecting the workpiece with a knife edge straight edge, the knife edge should be close to the measured plane of the workpiece, and then observe the size of the light transmission gap between the plane and the knife edge. If the light transmission is fine and uniform, the plane is straight. When checking the flatness of the plane, in addition to the longitudinal and transverse inspection of the workpiece, it should also be checked along the diagonal direction.
3. Feeler gauge: feeler gauge is a measuring tool composed of a set of thin steel sheets with different thickness, and the thickness dimension is marked on each steel sheet. The feeler gauge is mainly used to detect the gap between two joint surfaces, and can also be used with a 90 degree angle gauge to measure the perpendicularity error between adjacent surfaces of the workpiece.
When measuring the workpiece, select 1-3 feeler gauges to overlap according to the size of the gap, insert them into the gap, and measure the value of the gap. The feeler gauge piece with small thickness is very thin, which is easy to bend and break, and the force should not be too large when inserting. The surface of the feeler gauge should be wiped clean to avoid dirt affecting the accuracy of the measurement results.
5、 Smooth limit gauge
Limit gauge is a special measuring tool without scribed lines. It cannot measure the actual size of the workpiece, but can only determine whether the size of the measured workpiece is within the specified limit size range, so as to determine whether the workpiece is qualified. Limit gauges are used in batch and mass production.
Smooth limit gauge, limit gauge for hole dividing (also known as plug gauge) and limit gauge for shaft (also known as caliper gauge). Plug gauge is used to check the width of hole and groove, and caliper gauge is used to check the width of shaft diameter and convex key.