Use and measure with the caliper, vernier caliper or caliper

In this tutorial I will explain the use of one of the most commonly used instruments in the workshop to take measurements: the caliper, vernier caliper or caliper .
We generally use calipers to measure parts, screws, shaft diameters, holes, seals, and anything whose dimensions we need to know with a certain precision, which usually ranges from 0.1 mm to 0.02 mm depending on the instrument.

Different types for different needs
There are different types of calipers: universal (like the one we will use below), with graduated dial,

digital,

deep,

of gears...

The caliper allows us to take internal, external, and also depth measurements. To achieve maximum precision, it is essential that the caliper be positioned completely straight and level with the surface being measured.

Know the parts of the caliber
Even if it's just to gain a bit of technical knowledge, it's interesting to know the names of the different parts of this instrument.

1. Exterior feelers
2. Interior feelers
3. Depth sounder
4 and 5. Graduated ruler (in mm and inches)
6 and 7. Vernier caliper (in mm and inches)
8. Scroll button

Let's measure!
Let's explain how to take a measurement using a practical example. In this case, our caliper has a precision of 0.05 mm (0.05 mm).
We can see the value in the following photo:

In this case we see where the 0 mark of the vernier is and we count the complete millimeters on the ruler, so it would be 32mm.
Next we have to look at the only mark on the vernier that perfectly matches a mark on the ruler, in this case it would be 7, so the measurement value is 32 + 0.70 = 32.70 mm.

We see another example in the following image, where the 0 on the vernier is 8 mm behind and the vernier mark that exactly matches another on the ruler is the one between numbers 3 and 4, so we have 0.35 mm more.

In this case the measurement would be 8.35mm.
The following photograph indicates an exact measurement, since in this case both the 0 and 10 marks coincide with the ruler, and the measurement is 15.00 mm.

Instrument care
It's important to thoroughly clean the gauge after use, wiping it with a cloth slightly dampened with oil, as hand sweat is corrosive and can accelerate rust. For the same reason, it should not be stored with the feelers completely closed.
With these simple tips, you'll have a reliable precision instrument that will last for many years.

Frank Burguera

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