How to Use an Outside Caliper

What You'll Need
Outside Caliper
Object to be Measured
What You'll Need
Outside Caliper
Object to be Measured

An outside caliper is a precision device that is designed to take accurate external measurements of different objects. The caliper has bow-shaped legs that are specifically designed to measure spherical or oddly shaped objects, such as eggs, orbs, sculpture, and other 3D objects. While other types of calipers are designed to measure linear measurement on a single plane, the outside caliper is designed for 3D objects. The caliper can also be used to measure wider distances with accuracy.

Step 1 – Scout for an Outside Caliper

Outside calipers are not usually used by many DIYers and this makes them hard to find. The best place (and maybe the last place) to find them is in scientific supply stores. They can also be bought in some hardware stores and other supply stores. In some cases, they need to be ordered online.

Step 2 – Familiarize with the Caliper’s Parts

An outside caliper has a pair of jaws or arms that are bow-shaped. The bows curve inwards to allow the device to measure external dimensions. Inside calipers have a set of jaws that curve outwards. In contrast to the outside calipers, the inside calipers measure internal dimensions. The calipers are also designed to measure objects using different units of measurement. When buying calipers, it is best to check what unit of measurement it uses.

Step 3 – Check the Type of Mechanism Used

Each outside caliper makes use of a different mechanism to measure objects. There are calipers that engage a spring mechanism. Other calipers use a dial mechanism for easier reading. There are also calipers that have a locking device that can take/hold a measurement. The jaws of some calipers are secured by a joint. This type of caliper may become loose easily and provide wrong readings. Some calipers use a screw instead of a joint. A caliper which uses a screw to secure an object subject to measurement is better to use in most instances.

Step 4 – Calibrate the outside Caliper

Take an object and prepare it for measurement. Make sure that the outside caliper is working properly. To ensure that the caliper reads measurements correctly, close the caliper completely and check if the reading on the caliper scale is zero. If the reading is not zero, adjust the scale. If this is not possible, take note of the error and subtract the error from the final reading if the error is positive. If the error is negative, add it to the final reading.

Step 5 – Wrap the Caliper around the Object

Take the caliper, extend its jaws and wrap it around the object to be measured. When done, carefully tighten the jaws until the caliper is secured in place. Do this step carefully, especially if you are dealing with delicate objects, such as antiques.

Step 6 – Read the Measurement

Take note of the measurement that appears on the scale. Unlike other types of measuring devices, the outside caliper is a very precise instrument that can easily take outside measurements of several different types of objects with different shapes.