VERNIER CALLIPER (VERNIER CALLIPER) is a measuring tool for measuring length, inside and outside diameter and depth. Vernier callipers are composed of two parts: the main ruler and the vernier attached to the main ruler. The master ruler is generally in millimeter as a unit, and there are 10, 20 or 50 sub-grids on the vernier, according to the different sub-grids, vernier calipers can be divided into very degree vernier calipers, twenty degree vernier calipers, fifty degree grid vernier calipers, etc., vernier for 10 degrees of 9mm, 20 degrees of 19mm, 50 degrees of 49mm.

Before use, the workpiece must be measured surface and measuring claw contact surface wipe clean;

When measuring the outer diameter of the workpiece, the measuring claw moves outward, so that the distance between the two PAWS is greater than the outer diameter of the workpiece, and then slowly moves the cursor, so that the two PAWS are in contact with the workpiece. Avoid hard card hard pull, so as not to affect the accuracy of vernier calipers and reading accuracy;

When measuring the inner diameter of the workpiece, the measuring claw moves inward, so that the distance between the two external PAWS is less than the outer diameter of the workpiece, and then slowly moves the cursor outward, so that the two internal claws and the workpiece contact using method

When measuring, the vernier caliper should be perpendicular to the workpiece, and the locking screw should be fixed. When measuring the outer diameter, the minimum size should be recorded. When measuring the inner diameter, note down the maximum size;

When the workpiece depth is measured with depth vernier caliper, the fixed measuring claw is in flat contact with the measured surface of the workpiece, and then the vernier is moved slowly to make the measuring claw contact with the workpiece.

Use precautions：

A. Clean the measuring surface of measuring claw.

B. Check the interaction of each component; If the ruler frame and micromotion device move flexibly, fastening screw can work.

C, proofread zero. Make the caliper two claws close together, there should be no obvious light gap, the main ruler and vernier ruler zero line should be aligned.

D, at the end of the measurement to put the calipers flat, especially the large size of the calipers should be paid attention to, otherwise the ruler body will bend deformation.

E, vernier caliper with depth ruler, after use, to close the measuring claw, or the side of the thinner depth ruler exposed outside, easy to deformation or even broken.

F. After using the calipers, clean and oil them and put them in the caliper box. Be careful not to rust or get dirty.

G. If inaccurate or abnormal calipers are found, stop using them and report them in time. (Previously tested products must be remeasured).