JIANGSU ARTSTYLE DECORATION MATERIALS CO..LTD , https://www.artstyledecor.com In the use of the vernier caliper, uneven wear of the base surface of the ruler, uneven opening of the measuring surface, inconsistent indication values ​​of the upper and lower jaws, unstable gap of the measuring surface, and the like, bring an indication error to the caliper. The following is a brief introduction to several common defects and their repair methods: (1) There is no gap in the measuring surface when the claws are closed, and the indication error is verified.