Calipers Are? Here’s the understanding, Part Figure, function & how to read the measurement example of how to calculate the caliper
Measuring an object requires a special measuring instrument that can calculate the size of the object accurately and precisely. One type of measuring instrument that is quite well known is the calipers.
This tool is commonly used to measure length, but maybe not everyone is familiar with this measuring instrument. To help you understand what a calipers are and how to read calipers, here we explain the details of the review.
The Caliper Is ?
Before discussing further about this measuring instrument, you must first get to know it. Calipers are dimensional measuring instruments that are able to measure the distance, depth, and inner diameter of an object with fairly high accuracy, which is ±0.05mm.
In general, calipers have various names including ingsut crossbar, ingsut term, sigmat, scuiffmacth, vernier caliper, sliding term, sliding crossbar, and also the crossbar.
Then what level of accuracy does this sigmat measuring instrument have? Based on international units, the degree of accuracy that the calipers have is 0.1 mm ; 0.05 mm ; 0.02 mm and 0.01 mm.
This measuring instrument is generally used in the field of the engineering industry, starting from the design, manufacture to the final product checking process. This tool is widely used because it can present accurate and precise measurement results. In addition, this tool is relatively practical so it is easy to carry everywhere.
Calipers Section
In order to be able to use the vernier caliper to take measurements with accurate results, you must also know the parts of this measuring instrument. This tool consists of several parts that are very influential in the measurement process. Here are the parts of the calipers and their functions that must be known.

Upper Jaw
The first part of this measuring instrument is called the upper jaw. This jaw can be set to measure the diameter of an object. Therefore, this part can be shifted according to the shape and size of the object.

Jaw Lock
It is located behind the upper jaw. Its function is to lock the jaw so that it does not move so that the measurement results can remain accurate and precise because the measuring instrument does not move.

Main Scale
This is the main part of the vernier caliper. This section serves to read the results of the measurement values. This scale is the same shape and appearance as the reading scale commonly found on rulers.

Lower Jaw
The jaw part of this measuring instrument itself actually consists of one pair of jaws, namely the upper jaw and the lower jaw. Well, for this lower jaw its function is to measure the length of the object from the outside direction.

LongTerm Stalk
Next there is a section called the term stalk or the depth measuring stalk. Its function is of course to measure the depth of an object by moving its jaw.

Skala Nonius
If earlier on the main scale vernier caliper showed the results of measurements in both cm and mm, then this nonius scale showed a smaller scale. This nonius scale shows 1/10mm but there are also those that show a scale of 2/10mm.
That is, this scale is the smallest scale of those shown from the measurement results. On a nonius scale, 10 scales in length are 9mm. That way, for every two nonius scales located close to each other it is equal to 0.9mm.

Drive Wheels
The last part is called the driving wheel, whose function is to slowly move or make the jaw run. For more details, pay attention to the calipers image along with the name of each of the following sections.
Calipers Function
We often hear the question of what is the use of calipers? what is the calipers function used to measure? So the correct answer regarding the function and usefulness of the calipers is to measure the dimensions of objects with a shape and size (small) that cannot be measured with ordinary measuring instruments.
For example, thin objects, roundshaped objects or circular objects with cavities to tubular objects. All these objects will be difficult to measure if using ordinary measuring instruments.
Therefore, this measuring instrument is used. In general, this measuring instrument has quite a lot of functions. So it is not surprising that its use in everyday life, especially in the engineering industry is quite familiar. Here are some of its functions.

Measuring the Thickness of Small Objects
Objects with a thin thickness size are certainly very difficult if you have to measure using ordinary length measuring instruments. Therefore, to measure very thin objects such as plates, plates, zinc and so on, this tool is used.

Measuring the Outer and Inner Diameter of an Object
This is the next muchneeded function of the vernier caliper, which is to measure the outer and inner diameters of an object. Measuring the diameter of a roundshaped object can indeed use ordinary length measuring instruments. However, it only applies to a few objects only.
While circular objects with cavities will certainly be more difficult if you have to calculate with ordinary measuring instruments. So to make it easier and for the results to be accurate, this measuring instrument is used.
Types of Calipers
a. By Shape & Scale
After knowing the part of the calipers and their functions, the next thing to know is the types. A vernier caliper can be used to measure length magnitudes up to 0.1 mm or 0.01 cm.
Types of vernier caliper are divided into several more variants, that is, based on the shape of the scale and by its function or usefulness. First will be discussed the types based on the shape of the scale.

Manual Calipers
This first type has two types of scales, namely the main scale and the nonius scale or also known as vernier. The main scale is located on the fixed jaw section while the nonius scale is on the sliding jaw part. This type has an accuracy level of up to 0.1mm.

Analog Calipers
The second type of vernier caliper type by the shape of its scale is analogous. Generally, this type is the same as the manualterm type, but there are slight differences, especially on the nonius scale.
For analog types, the nonius scale is indicated by analog or resembles clockwork. This type has a precision level of up to 0.05mm and tends to be easier to read.

Digital Calipers
The last type is the digital calipers. Basically the shape is the same as the previous two types. The difference is in the nonius scale shown in the form of a digital screen. The advantages of this type are its easier use and a much more thorough level of accuracy, which reaches 0.01mm.
b. Based on Function & Usability
Next comes the type of vernier caliper type by function. These types are grouped by the measurement function or for what object the term is used. Here are the types.

HighAltitude Calipers
As the name implies, this type is used to measure the height of an object in more detail and accuracy.

Deep Groove Calipers
When viewed from the shape, this type of vernier caliper has a slight difference from the manual type, namely in the longer part of the jaw. Its function is to measure the inner diameter of a tube that is irregular in shape or squiggly.

Central Distance Calipers
This type of function is to measure the distance between a hole and the edge of the surface of an object. It can also be used to measure the distance of one hole to another.

Pipe Calipers
This next type of term is used to determine the thickness of tubes or pipes with a small diameter.

Disc Calipers
Next comes the type of disc, which serves to measure the thickness of the metal disc slab.

Gear Calipers
The last is the type of term used to take measurements to determine the thickness of the gears on machine spare parts or vehicle tools.
How to Use Calipers
although it has a main scale similar to a ruler, but the way this measuring instrument is used is different. Therefore, the following will explain the steps on how to use the vernier caliper that can be followed.
Before that, getting to know the parts of this measuring instrument as already described above will be very helpful. There are 3 ways to use the calipers related to the measurement model. Here’s the review:
a. Measuring the Outer Diameter

Open Jaw Lock
Generally, to be able to use this measuring instrument, the first thing to do is to open the jaw lock. If it is not opened, the jaw will not be able to be used to take measurements.

Place the Object to Be Measured Between the Jaws
If so, the next step is to place the object to be measured between the jaws. For example, if you want to measure the length of an object, then the jaw used is the lower jaw.
The object or object is located between the lower jaw and the fixed jaw. Place the object appropriately until both jaws on this measuring instrument touch the object to be measured.

Jaw Lock
Finally, lock the jaw using the key part on the jaw that has been shown in the previous figure. This locking aims to prevent objects from shifting so that the measurement results are more accurate. After that, the measurement results can be read.
b. Measuring Inner Diameter
 Turn the lock towards the left
 Insert the upper jaw into the object to be measured
 Slide so that the position of the jaw is right on the object to be measured
 Turn the lock so that the object does not shift / move
c. Measuring the Depth of Objects
 Turn the lock towards the left
 Open the jaw part until the tapered end is in contact with the base of the tube
 Rotate the lock to the right to lock so that the object does not shift its position
How to Read The Caliper
After knowing how to use it, you should also know how to read the results of the measurement of the vernier caliper. After performing the usage steps as described above, the measurement results will be displayed on the main scale.
You need to know that the caliper has an accuracy limit of 0.1 mm. That is, the measurement density using this tool can be up to 0.1 mm nearby. To read the calipers, you must know the 2 scales, namely the main scale and the Nonius scale. Here are the steps:

See The Zeros On The Nonius Scale
Previously, it was explained in the calipers section that there are two scales in this measuring instrument. There are main scales and nonius scales.
So the first step to read the measurement results is to pay attention to zero on the nonius scale. The main scale line that is just behind the zero of the nonius scale is the result of measurements on the main scale.

Read Values on the Nonius Scale
The value on the main scale is already known. The next way to read the calipers is to read on a nonius scale. Look at the lines that are located in a row between those on the main and nonius scales. The stringed lines indicated on the nonius scale are the measuring values.

Sum Both Values On The Scale
Finally, it remains only to add up the measurement results of the two scales. Also note the value equivalent to that shown on the measurement result line on the nonius scale. It is sometimes often forgotten.
Example of Reading the Results of The Caliper Measurement:
Take a look at the measurement image below! What is the diameter of the object measured using the following hollow?
From the longterm image above, we can see the nonius scale that is sandwiched with one of the main scales is 4 scales. This means that the figure has a value of 0.4 mm.
Next consider the Main scale. It is visible after the number Zero retreats backwards at the figure of 4.7 cm. So that the measurement diameter in the picture above is:
main scale + implicated nonius scale
= 4.7 cm + 0.4 mm = 4.74 cm.
Formula for How to Calculate Caliper Term
For the context of learning in schools, there will usually be examples of longterm problems. Examples of this question are usually in the form of pictures then students will be asked to calculate the measurement results using this vernier caliper measuring instrument.
To be able to solve this problem, you must know how to calculate the caliper. There is a certain formula that is used to calculate the measurement results using this measuring instrument, namely with the following formula.
Measurement Result = (nonius scale with x smallest scale of the caliper)
= main scale + (nonius scale x 0.01)
Notes : The smallest scale of this calipers can vary depending on the type used and what the level of accuracy is. Furthermore, we also explain the derivative formula for calculating the dimensions of objects:
Formula Measuring Vernier Caliper Dimensions : A=B+Zc
Where:
A = Length to be measured (CM)
B (Variable) = M+X (CM)
X (Variable) = n * LC (CM)
LC = Smallest count = 0.02 (CM)
Zc =Zero Correction= .07()—Let’s Assume a negative correction (CM)
M = Main scale reading (CM)
n = Number of vernier divisions coinciding with the division of the main scale
The following is an example of measuring the dimensions of a cylinder measured using a vernier caliper:
Si example  Main Scale( M)  Vernier scale division(n)  Variable X=n*LC.02  Variable B=M+X  Dimensi A=B+Zc 
1  10  5  5*.02=.10  10+.10=10.10  10.10+(.07)=10.03 
2  15  6  6*.02=.12  15+.12=15.12  15.12+(.07)= 15.05 
3  20  7  7*.02=.14  20+.14=20.14  20.14+(.07)= 20.07 
Source : www.riansclub.com
Example of Calculating the Caliper Term
After you know the steps and formulas for how to read the calipers, here we complete with a collection of examples of calipers complete with discussions for your study reference material.
 A beam is measured in width using a vernier caliper and gets the result as shown below. What is the width of the beam?
Discussion:
The line at the top indicates the main scale, while the line at the bottom is a nonius scale (additional scale. So the measurement above uses CM units. And the distance between each line on the main scale is 1 cm. So:
Measurement result = main scale + nonius scaleThe 0th on the nonius scale is between 1.9 and 2, so the main scale = 1.9 cm
The line on the nonius scale that is adjacent to the main scale line is the 8th line, so the nonius scale = 8 x 0.01 cm = 0.08 cm.( 0.01 cm = 0.1 mm is the limit of vernier caliper accuracy)So the measurement results = 1.9 cm + 0.88 cm = 1.98 cm
 Students from SMP Negeri 1 Malang received the task of measuring the thickness of the steel plate using a vernier caliper which obtained results as shown below.
What is the thickness of the steel plate measured by the student?
Discussion:
To start calculating, the first step you have to do is pay attention to the short line that is sandwiched between the main scale and the nonius scale (see figure )
From the picture obtained:Main scale = 0.9 cmFical scale = 8 x 0.01 = 0.08 cmThe measurement result = (0.9 + 0.08) cm = 0.98 cm = 9.8 mmSo the thickness of the steel plate measured by students of SMP Negeri 1 Malang is 9.8 mm
 What is the length of the object measured if the value of the main scale and the nonius scale looks like the figure below?
Discussion:
Blue circle = 5.3 cmRed circle = 5 x 0.01 = 0.05 cm Measurement result = 5.3 + 0.05 = 5.35 cm
 A metal is measured using a crossbar and has a measurement value as shown in the figure below. Determine the value of the measurement result!
Discussion:
Main Scale = 1.4 cmLessius Scale = 3.5Myest Scale = 0.05 mm Measurement Results := 1.4 cm + (3.5 × 0.05 mm)= 1.4 cm + 0.175 mm= 1.4 cm + 0.0175 cm= 1.4175 cm
 If the result of the measurement produced with the crossbar is 4.35 cm, the writing of the correct measurement result report according to scientific rules is?
Discussion:
The results of measuring a quantity are reported as:
x = x_{the} ± Δx
With :
x_{o} = readable measurement result
Δx = uncertainty of the measuring instrument. If to use the crossbar, then the uncertainty is 0.05 cm. Thus, the correct writing of the measurement result report is: (4.35 ± 0.05) cm.
Also Read: How to Calculate Screw Micrometer
That was a complete explanation of the calipers that can explain, ranging from meaning, function, types, sections to how to read and how to calculate it. With the explanation above, hopefully it can add to your insight into measuring instruments and how they are used.