Vernier caliper is a measuring tool for measuring length, inside and outside diameter and depth. The vernier caliper consists of a main ruler and a sliding vernier attached to the main ruler. Viewed from the back, the cursor is a whole. The main ruler is usually in millimeters, while the cursor has 10, 20 or 50 scales. Vernier calipers can be divided into 10-degree vernier calipers, 20-degree vernier calipers and 50-degree vernier calipers.

Composition of vernier caliper:

There are two pairs of movable measuring claws on the caliper and the main ruler of the vernier, namely, the inner measuring claw and the outer measuring claw. The inner measuring claw is usually used to measure the inner diameter, and the outer measuring claw is usually used to measure the length and outer diameter. The depth ruler is connected with the cursor to measure the depth of the groove and the cylinder. Among all kinds of measuring instruments, vernier caliper, as a widely used high-precision measuring tool, is the extension and expansion of the ruler originated from China.

Precautions for vernier calipers:

1, vernier caliper is a relatively precise measuring tool, so handle it carefully, don't bump or fall to the ground. Don't use it to measure rough objects, so as not to damage the measuring claw, and avoid putting it with the cutter, so as not to scratch the surface of vernier caliper. When not in use, it should be placed in a dry and neutral place, away from acid and alkali substances to prevent corrosion.

2. Wipe the caliper clean before measurement, and check whether the two measuring surfaces and cutting edges of the caliper are straight and undamaged. When the two measuring claws are closely attached, there should be no obvious gap, and the zero scribes of the cursor and the main ruler should be aligned with each other. This process is called calibrating the zero position of vernier caliper.

3. When moving the ruler frame, move freely, without looseness or tightness, without shaking. When fixing the ruler frame with the fixing screw, the reading of the caliper should not be changed. When moving the ruler frame, don't forget to loosen the fixing screw, not too loose to avoid falling off.