Caliper Ruler, How does a caliper work?

Caliper Ruler, How does a caliper work?
In recent times, quality has grown considerably in all products made by companies. In many products, for example screws, shafts, gears, plugs, among others, one of the properties that defines the quality of these products is measured in units of length.

This is why today's importance of having accurate measuring elements. Within the measurement tools of length, one of the most precise is the so-called caliper, king’s foot or Vernier.
Caliper Ruler, How does a caliper work?

What is a Caliper?

A caliper, king's foot or Vernier is a measuring tool that offers a pattern with which this pattern is compared with what you want to measure. It is mostly used to measure inside and outside diameters with greater precision than a common ruler is.

Precision of a Caliper

The precision of a Caliper is one tenth of a millimeter, that is, it is capable of dividing a millimeter into 10 parts. Compare this precision with that of a common rule. If we look at a common rule, we will be able to appreciate a value such as 1.5 cm, which is equal to 15 millimeters. While with the Caliper, we will be able to appreciate a value of 1.54 cm, which is equal to 15.4 mm.

On the other hand, even more precise Caliper’s can have accuracies of one twentieth of a millimeter (divide the millimeter into 20 parts) and a fifty-part of a millimeter (divide the millimeter into 50 parts).

What is a Caliper for?

A Caliper, as we mentioned at the beginning of this article, is a measuring tool that was developed in order to measure certain lengths with high precision. The Caliper also allows measurements "internal" and "external" thanks to its double mouth.

How a caliper ruler works

The operation of the Caliper is very simple. We will explain how to use it to obtain different measures of the same piece. Imagine a washer; we can get two measurements of this piece with the Caliper.

First, we open the outer jaws and place the washer between them. This measurement will give us the outer diameter of the washer. Then we do the same with the ears to measure interiors. In a case we close the ears, place the washer, and then open the ears until them, both meet the ends of the inside of the washer. In this way, we can achieve the measurement of the internal diameter of the washer.

How to read a Caliper

Once we have the measurement carried out as explained in the previous paragraph, it was time to read it. For this, we have three different scales. A main scale divided into cm and mm, a scale in inches, which we would not be interested in unless we wanted to measure in inches and a millimeter of millimeters (in the previous figure the number 6).

Let us see it with an example that will be easier. Imagine we have the following measurement.
Caliper Ruler, How does a caliper work?

We can see from the main scale that we are talking about 3.1 cm or 31 mm. What we must determine now is the tenth of a millimeter and we will determine this with the Vernier. We can see that in the Vernier we have a scale from zero to 10. We must look for the line that matches one of the stripes of the main scale. In case you do not get to appreciate, coincide in the 3rd line of the nonio.

With this, we can conclude that the tenth of the millimeter coincides in 3/10, so the exact measurement of this image is 3.13 cm or 31.3 mm.

Parts of a Caliper

  • External jaws for measurements of external parts of a piece
  • Internal Ears For measurements of internal parts of a piece
  • Needle for depth measurement. When you want to determine the depth of the hole of a piece.
  • Main scale. Scale with divisions in millimeters and centimeters with which we determine the first part of the measure.
  • Secondary scale it contains divisions in inches to be able to return measurement values in inches.
  • Nonio in millimeters. To determine the reading of the fraction of millimeters. Depending on how many fractions this division will determine the accuracy of the Caliper
  • Nonio in inches. To perform the same function as the Vernier in millimeters only when a measurement is made in inches.
  • Of sliding or brake. When open it allows the moving part of the slide gauge. When closed, it does not allow movement of the moving part.

Types of Caliper Ruler

  • According to the measurement to be performed
  • Standard gauges: Gauges that serve as a reference for manufacturing other gauges.
  • Calibration verification: Generally used for measuring finished parts.
  • Work Calipers: Used during work.

According to its operation

Caliper de rey universal: They are the traditional calipers. They have a great duration and a low cost by not using much tools.
Caliper Ruler, How does a caliper work?

Caliper king foot with clock. They are similar to universal king foot gauges only that they have a watch that allows immediate reading of the measurement value. It has the advantage of greater clarity in the readings, but it has the disadvantage that it does not have the possibility of measuring in inches.
Caliper Ruler, How does a caliper work?

Caliper digital king foot. They are the most modern gauges in the market. They have the great advantage that the measurement is shown directly by the screen and does not lead to errors by observation. It has the disadvantage that they are the most expensive in the market.
Caliper Ruler, How does a caliper work?

Differences between Caliper and micrometer

The caliper and the micrometer are both very precise measuring tools. Both measure lengths and return values in centimeters. What differentiates one from the other is the precision with which they measure. While the gauge has an accuracy of maximum 1/50 mm, the micrometer works with an accuracy of 1/100 to 1/1000 mm.