There are three main types: vernier calipers, dial calipers and electronic digital calipers.
①Vernier caliper. A ruler-shaped hand-held universal length measuring tool that uses the vernier principle to subdivide readings. It is mainly used to measure inner diameter, outer diameter, step and depth, etc. When measuring, the integer part of the value is read from the main scale, and the decimal part is read from the vernier scale. The principle of the vernier is to use the difference between the engraved line spacing on the main scale (referred to as line spacing) and the line spacing on the vernier scale to read the decimal part. There are three minimum reading values ??of 0.02mm, 0.05mm and 0.1mm.
②With watch caliper. It is a large hand-held length measuring tool that uses the tooth pitch of precision racks and gears as the known length, and uses the indicator table with corresponding graduations as the amplification, subdivision and indication part. Calipers with gauges can solve the problem of reading errors of vernier calipers. Common minimum reading values ??are 0.01mm and 0.02mm.
③Electronic digital caliper. It is a length measuring tool that uses measuring systems such as capacitive grating and magnetic grating to display the measurement value digitally. The commonly used resolution is 0.01mm, and the allowable error is ±0.03mm/150mm. There are also high-precision digital calipers with a resolution of 0.005mm and an allowable error of ±0.015mm/150mm. There is also a multi-purpose digital micrometer caliper with a resolution of 0.001mm (this is the national patent of Anyi Measuring Tools and only they can produce it), with an allowable error of ±0.005mm/50mm. Because the readings are intuitive and clear, the measurement efficiency is high.
In addition, there are various non-standard calipers, such as hook depth calipers to measure groove depth, tooth thickness calipers to measure gear thickness, height calipers to measure the height of objects, and welding calipers to measure welding quality. Seam caliper (weld gauge), etc.
A caliper has four main functions, as follows:
a. Outer diameter measurement (lower/outer measuring claws), b. Inner diameter measurement (upper/inner measuring claws), c. Step measurement (left head), d. Depth measurement (tail depth needle)