A caliper is the most universal and easy in handling precision measuring instrument. Using it, you can measure external and internal dimensions as well as hole depths or ledges. At the same time, modern digital calipers show measurement results on their display instantly. It is a pleasure working with such an instrument.
Main types of calipers
Vernier calipers. Such calipers have a main and additional (vernier) scale for counting graduation. This is the simplest caliper type. It is also called columbus in honor of the company «Columbus» which supplied calipers under Lend-Lease. Such a caliper is used for external and internal measurements, measuring hole depths and ledges, creating markings.
Dial calipers. In a dial caliper, the size in millimeters indicates the frame edge and millimeter fractions indicate a dial type. Such an instrument is typically used when more accurate measurements are necessary. It is more expensive than a vernier caliper and requires careful storage.
Digital calipers. In this case, measurement results are displayed. This instrument allows you to set zero in required positions. Using such a caliper is time-saving thanks to instant measurement results.
How to choose a caliper
– First of all, it is necessary to determine a measuring range. For amateur use a tool with a measuring range of up to 300 mm is suitable, however, in factories they use a tool with a measuring range up to 3000 mm.
– An important factor is resolution, since measuring accuracy results depends on it.
– Measuring speed saves time while obtaining results. However, keep in mind that dial and digital calipers cost more than vernier ones.
Keep in mind when choosing a caliper:
– Jaws. They should be even and there should be no gap between them when closing.
– Material of jaws. It should be durable enough.
– Vernier. The scale must be set to zero and graduation must be clearly visible.
– Frame material must not attract metal chips. It ensures product durability.
– Accompanying documents. An instrument must have a passport and calibration information.