Vernier calipers are very accurate tools for measuring linear distances between 100 and 300 millimetres. Their main applications are in industrial, automotive and scientific work. Calipers have moveable jaws that span the area so you can measure them in different ways. The outside of the jaws is for measuring gaps and holes, while the inside clamps across an object to measure its width, length or thickness. The resolution of vernier calipers means the distance between the smallest markers on the scale. It is usually 0.02 or 0.05 mm. Some calipers display both metric and imperial measurements, which is useful when you use a mix of products from countries with different measurement systems. The jaws usually have a locking screw to retain accuracy. Vernier calipers come in different sizes, the bigger ones for longer measurements. You can also get models of calipers that are waterproof, coolant proof, shockproof and even solar powered. It's important to know the difference between 3 types of vernier calipers: digital, dial and manual.Digital Electronic Vernier Calipers
Although people call them digital vernier calipers, they are not verniers but simply digital calipers. In this type, the sliding jaw mounts with a plastic runner containing a digital LCD display. The unit uses a small battery, usually 1.55 volts. One convenient feature of digital calipers is that you can make the display show you metric or imperial measurements. Like the other types, they have a locking screw to stabilize the measurement for reading.Dial Vernier Calipers
Dial vernier calipers are just as accurate as digital calipers. They have a linear scale for centimetres but also a dial like a watch face. It has a needle that can measure in smaller units, such as tenths of a centimetre. Therefore, you can go down to very small measurements with accuracy.Manual Vernier Calipers
Manual vernier calipers have no electronics or dials, but they are just as accurate and can do the same jobs. You manually slide the jaws together and secure with a locking screw. Dial calipers have the advantages of being less expensive than the other types of vernier calipers, as well as being robust and not needing batteries.