# Uses of Vernier Calipers

Vernier calipers are used to measure the distance between objects. They are used to measure the dimensions of an object. They can measure both internal and external dimensions accurately. They are used to measure exact linear measurements in various fields.

Firstly, the clips of the vernier calipers are adjusted so that they can fit across the object that needs to be measured. Then, after marking the dimensions on the vernier calipers, it is removed, and the dimensions are measured with a ruler. It can also measure circular and cylindrical objects by placing its jaws around the circumference of the object. This makes it an important toolkit for every engineer.

The primary scale of the vernier calipers is marked at one jaw, while the secondary scale is marked above the primary scale. Therefore, the value should be zero when the two jaws contact each other. If this value is not zero, then the chances are the calculations may have positive or negative errors.

## Range and least count of a Vernier caliper

The maximum capacity of a Vernier caliper is determined by the difference between its largest and smallest measurement readings. The standard range of a Vernier caliper is 300mm. Vernier calipers ranging from high to low in terms of capacity and accuracy are available in the market.

Least count – The smallest count or reading obtained with the instrument can be computed as follows:
Least count = one main scale division (MS) – one Vernier scale division (VS)
= one main scale division/number of divisions in vernier scale.

## Using vernier calipers

A vernier caliper is mostly used to measure circular objects. The jaws of the vernier calipers are placed around the circular object, tightly fit around it, and the readings are taken from the main and secondary scales. The major scale or the primary scale has measurements in millimeters, measuring up to 0.001cm.

## Various parts in a vernier caliper

1. The Primary Scale: It is made out of a steel metallic strip graded in centimeters on one edge and inches on the other. It        is equipped with both the inner and outer measuring jaws. When the two jaws inherit contact, the zeros of the focal scale      and the vernier should line up. Positive or negative zero mistakes can occur if two zeros do not coincide.
2. Vernier Scale: A vernier scale slides on the strip. The retainer allows it to be fastened in any position. 0.9 cm is split into     10 equal pieces on the Vernier scale.
3. Outer Measuring Jaws: The outside measuring jaws take an object's exterior dimension.
4. Inner Measuring Jaws: The inner measuring jaws take an object's interior dimension.
5. The Retainer: The retainer keeps the item in the Vernier calipers' jaws.
6. Depth Measuring Prong: The depth measuring prong determines the depth of an item.

## Applications

The main purpose of the vernier caliper is to measure the distance between objects, and their internal and external dimensions, including height. The resolution of a vernier caliper is up to a tenth of a millimeter. Vernier calipers usage includes the following sectors-

1. Education sector – used to measure materials undergoing temperature changes, measure regular and irregular objects.
2. Science labs – used to measure apparatus present in science labs for error-free experiments.
3. Medical applications – used to measure tools used in surgeries and medical usages.
4. The steel sector is used to measure the length, breadth, and height of objects to make consistent products of the same dimensions.
5. Aerospace sector - used to measure even minute details in the aerial parts to avoid accidents in the air. These vernier calipers have high precision that gives more accurate readings.

Other applications include-

• The inner jaw can measure interior dimensions such as pipe inner diameter, seals, and washers.
• To measure shaft diameter, keyway dimensions, shaft length.
• The depth or length of the bottle or beaker can be measured by using the stem.
• The vernier caliper operates on the concept that when two scales or divisions of slightly different sizes are used, the difference between them improves measurement accuracy.
• For measurement of Slots, undercut groves.
• We can measure the length of a rod, the diameter of a sphere, and the outer diameter of a hollow cylinder with the vernier's outer jaws.
• Measurement of workpiece thickness.