Accuracy in Calipers – Calipers are a measuring instrument that has a very good or accurate level of precision and accuracy. Calipers can be used if an object cannot be measured using a ruler.
In general, the function of the calipers is as a measuring tool for an object, between measuring the outer and inner diameters of objects, measuring the length of objects that are small in size and measuring the depth of objects.
So, how do you read a caliper as a measuring tool and what is the level of accuracy of this caliper? Check out the explanation about the caliper below!
A Brief History of the Sorong Term
The earliest vernier calipers were found on the Greek wreck of the Giglio off the coast of Italy. According to recorded data, the Greek ship Giglio dates from the 6th century BC.
The piece of wood from the vernier caliper already has jaws that are fixed and can be moved. Although rarely found, calipers were still used by the Greeks and Romans.
After the invention of wooden vernier calipers, bronze calipers were invented in 9 AD. these bronze calipers were used to measure small objects during the Xin Dynasty in China.
The vernier caliper has an inscription stating that the vernier caliper was made on the day of Gui You, namely the first day of the first month in the first year of Shijianguo. Calipers including slots and pins and caliper precision in inches and tenths of an inch.
The vernier caliper currently used was invented by Pierre Vernier as a development of the vernier scale or the nonius scale of Pedro Nunes.
Definition of shove term
As previously explained, that caliper is a measuring tool to measure the length, outside diameter and inside diameter of an object. In addition, calipers can also be used to measure the depth of holes and geometric shapes, such as tubes.
Calipers are more often used to measure objects that are small in size and cannot be measured by other measuring instruments such as a ruler. So, it can be said that the level of accuracy of this caliper is higher when compared to a ruler.
The level of accuracy of the caliper in question is the smallest scale value that can be measured. For vernier calipers, the smallest scale value is 0.01 cm or 0.01 mm and this scale is different from a ruler whose smallest scale reaches 0.1 cm or 1 mm.
This is the advantage of this caliper. In addition, because of the right size and easy to carry anywhere, the vernier caliper has become a reliable measuring tool for workers in the engineering field.
Parts of the Caliper
Before discussing the accuracy of the caliper further, Sinaumed’s needs to know the parts of the calipers first.
The vernier caliper has two parts, namely the fixed jaw and the sliding jaw, the vernier caliper is different from the ruler which only has one reading scale, because the vernier caliper has two reading scales.
The two reading scales consist of the main scale and the vernier scale or commonly known as the nonius scale. The main scale of the caliper tends to be longer and is located on the fixed jaw. While the nonius scale is a short scale that is on the sliding jaw.
To make it clearer, here is an explanation of the parts of the caliper.
1. Deep jaw
This section consists of sliding jaws and fixed jaws. The inner jaw has the function of measuring the inside, such as the diameter of the hole or gap.
2. Outer jaw
This section has two parts, namely the sliding jaw and the fixed jaw. The function of the outer jaw is to measure the outside, such as the width, length and diameter of an object.
3. Stalk depth gauge
The third part of the vernier caliper is the depth measuring rod which has the function of measuring the depth of the hole of an object.
4. Main scale
The main scale of the caliper has a function to express the main measurement results, usually the main scale of the caliper is expressed in inches or cm. Generally, the length of the main scale of the calipers reaches 15-17 cm.
5. Nonius scale
This scale has the function of adding an extra level of accuracy to measurements. In general, the nonius scale is expressed in inches or mm.
6. Locking bolt
The bolt on the calipers has the function of holding the jaws in place. The goal is that the object being measured can be held or not released and the scale will not shift when measuring.
How to use and read caliper
In general, how to use a vernier caliper to measure the length or outer diameter of an object is as follows.
- Check first then make sure both jaws are closed, the scale will show zero. The goal is that there is no error in measurement which is commonly referred to as zero error.
- Then loosen the locking bolt, then pull the sliding jaw to the right, so that the object that Sinaumed’s wants to measure can be placed between the two jaws, fixed and sliding.
- Place the object you want to measure between the two jaws, then make sure the object’s position is appropriate.
- Pull the sliding jaw of the caliper to the left until it clamps the object to be measured, then rotate the locking screw until you hear a click.
- Then read and calculate the caliper measurement results obtained.
Then, how do you read and calculate the correct caliper? Here’s an explanation.
- Record the value shown on the main scale that results when measuring objects.
- Then pay attention to the value on the right nonius scale and parallel to the main scale, then determine the value by multiplying the result of the nonius scale by 0.1 mm.
- After that, add up the values on the main scale with the nonius scale.
To make it easier to calculate the measurement results from caliper, Sinaumed’s can use the following formula.
To determine the smallest scale value or NST, Sinaumed’s can determine it using the following formula.
NST = The smallest scale value of the main scale: the sum of the nonius scale.
For example, on a caliper the distance from scales 4 and 5 is 1 cm, then between scales 4 and 5 there are 10 scale lines. So, the smallest scale value of the main scale is as follows.
1 cm: 10 = 0.1 cm. The smallest scale of the caliper is 0.1 mm or 0.01 cm.
Next, look at the nonius scale. On the nonius scale there are 50 scale lines, then the NST of the caliper is as follows.
NST – 0.1 cm :50
= 0.002 cm
= 0.02 mm
Accuracy in Callipers
After knowing the definition, the parts of a vernier caliper and how to use and measure a vernier caliper, Sinaumed’s needs to understand the accuracy of a vernier caliper.
Each measuring instrument has a different level of accuracy, the level of accuracy is the ability of an instrument to provide measurement results that are closest to the actual size of the variable being measured.
Likewise with the vernier caliper measuring instrument, the vernier caliper also has a certain level of accuracy that can be achieved when used in measurements.
The level of accuracy possessed by the calipers is 0.1 millimeters or mm or 0.01 cm. The accuracy value of the vernier caliper is obtained through the smallest scale line or nonius caliper scale which has a distance of 0.1 mm from one another.
The accuracy of the vernier caliper is better than a ruler or ruler which only has an accuracy of 1 mm or 0.1 cm. However, it is below the micrometer screw with a caliper accuracy of 0.01 mm or 0.001 cm.
Because it has better accuracy than a ruler, calipers have several advantages. Among them are as follows.
- Able to measure the outside diameter, for example like marbles, pencils and other tube objects.
- Calipers have an inside diameter, for example in measuring rings or pipes.
- Calipers are able to measure the depth of objects, for example, the depth of cylindrical objects such as glasses and pipes.
Types of Calipers
In general, calipers can be divided into two, namely analog calipers and digital calipers.
Analog calipers have a sliding part called the stroke scale. The scratch scale in the analog calipers is divided into two, namely the nonius scale or the vernier scale and the main scale. Nonius scale readings on analog calipers are carried out simultaneously.
As for the digital caliper, it is a caliper that can display the size directly in digital form.
Using digital vernier calipers is very easy when compared to analog calipers, because the user does not need to use a formula to find out the measurement results, because the measurement will be directly displayed on the digital vernier caliper screen.
Apart from these two general types of calipers, there are two other types of calipers. Following are the types of caliper.
- Hourly caliper or watch slide caliper
This watch slide caliper is a caliper whose reading uses an analog needle attached to the face with a vernier caliper stopper. The vernier caliper uses a measuring clock as a substitute for the nonius scale in interpolating the position of the index line on the measuring rod scale. - Altitude caliper
Another type of caliper is the altitudinal caliper. This vernier caliper is a kind of vernier ruler which has the function of measuring height, so this vernier is called a vernier caliper or a vernier caliper with a high caliber.
The high calipers are equipped with measuring jaws that have a vertical movement on the stem with a scale that is perpendicular to the anvil.
The surface of the measuring jaw, made parallel to the base. So that the measuring line will be perpendicular to the surface above, where the foundation is placed.
Therefore, when using calipers at this height, a flat surface is required as a reference, in this case the intended flat surface can be a flat table.
In addition to the four types of calipers, the types of calipers can also be divided into six if they are distinguished based on the function of the calipers. Here’s an explanation.
- Deep groove caliper
The first type of caliper is the deep groove caliper. This caliper has a longer jaw shape when compared to manual or analog caliper jaws.
The function of the inner groove caliper is to measure the inside diameter of a tube that has a squiggly or uneven shape, such as a bottle or jar. - Pipe vernier caliper
Pipe vernier caliper, usually used to measure the thickness of tubes and pipes that have a small diameter. - Center distance vernier caliper
Center distance vernier caliper is used to measure the distance between one hole and another or the distance between a hole and the edge of an object surface. - Gear calipers
As the name implies, gear calipers are used to measure the thickness of the teeth on the gear, which will generally be found on vehicle tools or on machine spare parts of a particular object. - Disc caliper
The disc caliper has the function of measuring the thickness of a metal plate or disc. - Altitude caliper
The last type of caliper based on its function is the height calipers. As previously explained, the caliper serves to measure the height of an object more accurately and in more detail.
In height calipers, calipers are equipped with measuring jaws that have a vertical movement on the stem with a scale that is perpendicular to the base.
The principle of how the shove term works
The main principle when using a vernier caliper is that if the key on the vernier caliper is loosened, the board of the nonius scale can move as needed when measuring certain objects.
Then to measure certain objects, the caliper will clamp between the two clamps or jaws on the caliper as accurately as possible or according to the position that fits the object being measured.
The results of the size of the object can be determined directly by reading the main scale down to one tenth of a cm or 0.1 cm. After that, add the results from the reading on the nonius scale to one thousandth of a cm or 0.001 cm. Calibration of the calipers is carried out by pushing the sliding jaws so that they touch the upper jaw.
The caliper can be said to have been perfectly calibrated, if the sliding jaw is in the right position at zero, that is, the zero on the main scale and the zero on the nonius scale totally coincide with one straight line.
If it has been perfectly calibrated according to the description above, the caliper is ready to be used to measure a certain object.
In practice the working principle of a sliding caliper, this compass has advantages and disadvantages when it will be used to measure certain objects.
The advantages of vernier calipers are that they have accuracy in reading, they can easily measure the outside and inside diameters, they can measure depth more accurately and vernier calipers can be had at a low and affordable price compared to other measuring instruments.
On the other hand, vernier calipers also have drawbacks, including not being able to measure large objects and expansion of the caliper material can occur if not treated.
That is an explanation of the accuracy of the caliper and an explanation regarding the caliper.
If Sinaumed’s still has difficulty understanding how this tool works or how to read it, Sinaumed’s can read reference books that make use of calipers such as Physics textbooks.
Thus a review of accuracy in caliper. Sinaumed’s can get related books at sinaumedia.com . As #FriendsWithoutLimits, sinaumedia provides the best products for Sinaumed’s.