Precautions for using gauges
The gauge is a kind of precision measuring instrument. During the process of using the gauge, it has to be in contact with the workpiece multiple times. How to maintain the accuracy of the gauge and improve the reliability of the inspection results has a great relationship with the operator, so the gauge must be used reasonably and correctly.
1. Check carefully before use. First check the drawings to see if the gauge is in compliance with the required inspection dimensions and tolerances, so as to avoid errors and cause a large number of waste products. At the same time, check whether the gauge has a qualified mark or other Proof. Also check whether there are rust spots, scratches, burrs and other defects on the working surface of the gauge, because these defects can easily cause the surface quality of the inspected workpiece to decline, especially the non-ferrous metal workpiece with higher tolerance grade and surface roughness. Also check whether the connection between the gauge probe and the handle is firm and reliable. Finally, check the inspected part of the workpiece (especially the inner hole) for burrs, bumps, scratches and other defects. 2. Before use, clean it Use the fine cotton yarn or soft cloth to wipe the working surface of the gauge, and allow a thin layer of oil to be applied to the working surface to reduce wear. 3. Before use, you must distinguish which is the end and which is the end. Don't make a mistake .4. When using the gauge, the correct operation method of the gauge can be summarized as "light", "positive", "cold", and "full". Light, that is, when using the gauge, it should be handled with care, safe and reliable; not at will Throwing; do not collide with the workpiece, and then inspect the workpiece after it is stable; during the inspection, light jam and light plugging, not hard jamming. Positive, that is, when the gauge is inspected, the position must be placed upright, not skewed, otherwise the inspection result will not be Reliable. Cold means that the inspection can only be carried out when the temperature of the inspected workpiece and the gauge is the same, and the workpiece that is hot after processing cannot be inspected; the precision workpiece should be isothermal with the gauge. All, that is, the inspection of the workpiece by the gauge must be comprehensive. To obtain correct and reliable inspection results, the plug gauge through end must be inspected over the entire length of the hole, and it must be inspected in 2 or 3 axial planes; the plug gauge end must be inspected at both ends of the hole as much as possible. The through end and the stop end of the gauge should be inspected at no less than 4 positions along the axis and around the axis. 5. If the plug gauge is stuck in the workpiece hole, it cannot be hit with an ordinary hammer, twisted or smashed by a wrench. , Otherwise it will damage the working surface of the plug gauge. At this time, use wood, copper, aluminum hammer or fitter removal tools (such as pullers or pushers), and pad a piece of wood or copper on the end surface of the plug gauge. Protect, and then pull or push out forcefully. If necessary, the outer surface of the workpiece can be slightly heated, and then the plug gauge can be pulled out. 6. When the workpiece clamped on the machine tool is still running, it cannot be checked by the gauge. 7. Do not use gauges to inspect workpieces with rough surfaces and unclean surfaces. 8. The through end of the gauge must pass through each qualified work piece, and its measuring surface is often worn. Therefore, the gauge needs to be checked regularly. For working gauges, when the plug gauge is close to Or exceed its minimum limit, when the through end of the caliper (ring gauge) approaches or exceeds its maximum limit size, the workpiece gauge should be changed to an acceptance gauge for use. When the acceptance gauge is close to or exceeds the wear limit, it should be immediately scrapped and stopped using it. 9. Use the smooth limit gauge to inspect the workpiece. If it is determined that there is a dispute, the following size gauge should be used for inspection;
