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Understanding Vernier Caliper

In projects where accurate measurement must prevail, a vernier caliper must come into use. The lathe machinist can relate better because 95% of lathe operations are measured using a caliper. This is to say, it is a special tool for lathe operators. Today you’ll get to know the definition, history, working of a vernier caliper.

Vernier calliper diagram

Read more: Common types of precision measuring instruments

What is a vernier caliper?

Vernier caliper which is also known as the vernier scale is a measuring device that is used to get a precise measurement of linear dimensions. In other words, it measures a straight line between two points.

It is also applicable when trying to take the dimension of round objects and can also measure the depth of a hollow part. This is to say, a vernier caliper can be used to take three different measurements, which include, depth, width, and linear parts.

It can also be seen as a visual aid for taking an accurate measurement reading between two graduation markings on a linear scale. It is done by increasing resolution and reducing measurement uncertainty by using vernier acuity to reduce human estimation error.

Read more: Everything you need to know on Micrometer screw gauge

History

The vernier caliper or scale was invented in 1631 by French mathematician Pierre Vernier. Its part is used together with the main scale, given precise measurements at proper use.

They are useful tools that must be found in an engineer’s toolbox. It contains a fixed main scale and a moving vernier scale. This main scale is labeled in millimeters or tenth of an inch. The precise measurement of a vernier caliper is due to its ability to take a reading typically 0.02mm or 0.001 inch.

The resolution of a vernier caliper is the smallest distance that the caliper can measure. The resolution of imperial vernier calipers is usually 0.001 in, whereas the resolution of metric calipers is either 0.05mm or 0.02mm. Typically, the caliper’s resolution is indicated at the end part of the vernier scale.

Read more: Types of Measuring and marking-out tools and their uses  

Measuring Range and Tolerance

A vernier caliper measurement range is the difference between the largest and smallest value that a caliper can measure. The caliper range is sometimes called the maximum capacity of a caliper, which is equal to the length of the main scale. Most vernier calipers have a range of 6 inches (300mm). However, calipers are available in smaller and larger ranges.

Vernier calliper measuring range

Discussing tolerance or instrument error vernier calipers are good at that, same as micrometers. They are tools purposely designed for low tolerance measurement. Low tolerance measuring tools are known for their very accurate measurements.

As for vernier calipers, their instrument error is mostly +- 0.03mm (+- 0.0015 in). As you see that is quite tolerated, with the capability of measuring outside dimensions, inside dimensions, and depth. Some calipers with incorporate the Quadri feature are used to take step measurements.

Read more: List of Benchwork hand tools and their uses

Watch the video below to learn the working of a vernier caliper:

 Digital Vernier Calliper

Finally, the advancement of technology help with the development of the Digital Vernier Calliper. These digital calipers offer very accurate measurements, even more than the traditional ones. But it is a little more expensive, maybe that’s why users prefer traditional calipers.

The Digital vernier calliper

 

The digital vernier caliper takes measurements with a series of capacitance sensors that move around the beam length. The sensor will detect a change in the electrical charge when a change occurs in the distance of the jaws.

That is all for this article, where the definition, diagram, and working of a vernier caliper are being discussed. I hope you get a lot from the reading, if so, kindly share with other students. Thanks for reading, see you next time!

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