1. When there are burrs on the surface of the workpiece, be sure to remove the burrs before measuring, otherwise the measuring tool will be worn and the accuracy of the measurement results will be affected.
      2. Do not use whetstone or emery cloth to rub the surface of the measuring tool, the measuring surface and the engraved line. Non-measuring maintenance personnel are strictly prohibited from disassembling, modifying and repairing the measuring tool without authorization.
      3. It is not allowed to use the tip of the measuring claw of the caliper as a needle, compass or other tools, and it is not allowed to manually twist the two claw or use the measuring tool as a card board.
      4. Do not touch the measuring surface of the measuring tool with your hands, because wet dirt such as sweat on your hands will contaminate the measuring surface and cause it to rust. Do not mix the measuring tool with other tools and metal materials to avoid bumping the measuring tool.
      5. The storage location of measuring tools should be kept clean, dry, free from vibration and corrosive gas, and away from places with large temperature changes or places with magnetic fields. The measuring tools stored in the measuring tool box should be clean and dry, and other sundries are not allowed.
     6. After using the measuring tool, clean the surface stains and aluminum chips, loosen the fastening device, and apply anti-rust oil on the measuring surface when it is not used for a long time (more than 1 month). When the measuring tool is not in use, it should be put into the protective box, it is best to be used by a dedicated person, and the annual audit record of the measuring tool tested by the authoritative unit should be made.