is a universal measuring device for determining the linear dimensions of parts with established accuracy. It can be used to measure external and internal dimensions parts, as well as the depth of the holes, subject to the presence of a retractable rod.
Design and use of calipers
The most popular areas of application for calipers are construction, repair of machinery and equipment, processing of metal and wooden products. The scope of application has virtually no restrictions - it can be used to determine dimensions with an accuracy of 0.1 or 0.05 mm (depending on the type of tool) in any field of activity - both in everyday life and in the aerospace industry. Application possibilities are limited only by the scale size and accuracy requirements (up to 0.01 mm for electronic calipers).
The design of a caliper is quite simple. The main element is a fixed rod with a scale and jaws for external and internal dimensions, to which movable and fixing elements are attached.
- Mobile frame;
- Movable jaws to determine the internal size;
- Movable jaws to determine the outer size;
- Vernier scale;
- Depth gauge rod;
- Screw for fastening the frame.
Some models may have a moving scale at the top with an inch measurement system.
How to take readings using a caliper
Before starting work, it is necessary to check the caliper for accuracy. To do this, you need to completely bring the jaws together and check that the zeros on both scales match. If there is no coincidence, then, depending on the required accuracy, it is necessary to either take another tool or take into account the existing error.
- To measure the external size, spread the jaws of the caliper, place the object and connect them.
- Measuring the internal size is carried out by placing the corresponding upper jaws inside the measured area and moving them apart until they stop
- The jaws should rest against the edges of the part. If the surface is hard, then you can squeeze it a little for a tight fixation; for a soft one, this should not be done, as the result can be distorted.
- Check the position of the caliper relative to the part being measured for any distortions. To do this, the jaws must be located at the same distance from the edge of the part.
- Secure the vernier with the mounting screw.
- Determine the whole number of millimeters on the main scale.
- We find the coincidence of the stroke on the vernier with the zero of the main scale and count the number of divisions.
- We multiply the number of divisions of the vernier by the value of the division and sum it with the value of the main scale.
Types of calipers
In general, all types of calipers can be divided into mechanical and electronic depending on the type of scale. The main types, according to GOST 166-89, are:
- ШЦ-I - a tool with 2-sided placement of jaws for measuring external and internal quantities and a depth gauge.
- ШЦК - equipped with a circular scale to determine the exact size. Easier to use than vernier calipers.
- ShTsT-I - one-sided jaws for measuring external linear dimensions. It is highly resistant to wear.
- ШЦ-II - equipped with two jaws for external and internal measurement and marking, as well as a micrometric feed frame.
- ШЦ-III - one-sided jaws for determining external and internal dimensions.
- SCC - electronic caliper with digital display.
Technical condition and verification of calipers
One of the most important requirements for ensuring the accuracy of a tool is its cleanliness. A magnetized layer of metal filings, preservative lubricant, dirt - all this can significantly distort the measurement result. The result is also affected by tool wear, deformation, and settings violations. To avoid this, it is necessary to have the caliper checked annually at a specialized service center with repairs and adjustments. The simplest check for the correctness of the readings is the coincidence of the zero strokes when the jaws are completely closed.
Current GOSTs
The production and verification of tools is regulated by a number of state standards. Yes, it determines technical specifications on calipers GOST 166-89. The instrument verification procedure is defined in GOST 8.113-85.
In production construction work or minor repairs Measuring tools are often required. Usually they are rulers or tape measures. But when measuring pipe diameter or hole depth, these tools are not suitable. For such purposes, more precise measuring instruments are used - calipers.
This device is universal. It can be used to measure the external and internal dimensions of parts. Calipers have gained wide popularity in everyday life, as they have a simple design and are easy to use. Using such a device, you can quickly and easily take measurements with high accuracy.
Vernier caliper device
1 — Sponges for internal measurements
2 — Sponges for external measurements
3 - Clamping screw
4 - Movable frame
5 - Vernier
6 - Rod
7 — Bar scale
8 - Depth gauge
All instruments similar to calipers have a measuring rod, which is how the device gets its name. There is a main scale on the rod, which is necessary when measuring first.
A movable frame with a printed scale can move along the bar. The scale on the rod is called a vernier, which has more precise markings in fractional divisions. This provides increased measurement accuracy. The degree of accuracy of a caliper, depending on the design, can reach hundredths of a millimeter.
Calipers have two types of jaws:
- For measuring internal dimensions.
- For measuring external dimensions.
There is also another measuring element of the device, which is called a depth gauge. It can be used to measure hole depth and other dimensions.
Digital calipers are designed in a similar way. However, instead of a vernier, a digital scale is used, which increases the ease of use and measurement accuracy of the device.
1 - Clamping screw
2 - Battery
3 - Roller length change
4 - Reset
5 - On/Off
6 - Switch mm/inches
Like all measuring instruments, digital instruments are equipped with a scale with a division value of 0.01 mm. The permissible error is considered to be a deviation of the measurement result down or up by 10%. In industry, all measuring instruments are subject to metrological control every six months.
The retail chain sells calipers packaged in a case. When purchasing a tool, it is recommended to inspect the measuring jaws. They should be smooth, and there should be no gap when they are compressed.
The vernier scale should be in the zero position when the jaws are closed. The lines marking the scale divisions along the vernier must be clearly marked. The kit of the device must include a passport with a mark on the accuracy verification performed.
Types and features
Main types of calipers:
There are several subtypes of different calipers depending on the size, design features and operating principle. Below we consider the main types of such measuring instruments.
ШЦ-I
This is the simplest and most popular model of the device, which is widely used in industrial production. It is called a “Columbian” after the name of the manufacturer that produced the instrument during wartime (Columbus).
The device can measure internal and external dimensions and depth. The measurement interval is from 0 to 150 mm. The measurement accuracy reaches 0.02 mm.
SCC-I
This digital measuring tool model has a similar design to the classic caliper. Measurement interval 0-150 mm. One of its advantages is higher measurement accuracy due to the presence of a digital indicator.
The convenience of using such a digital device is that the indicator can be reset to zero at any measurement point. You can also easily switch from metric to inch with just one button.
When purchasing a digital model, you need to pay attention to the presence of zero readings when the jaws are closed, and also when the locking screw is tightened, the numbers on the display should not jump.
ShTsK-I
In this design of the caliper there is a rotary indicator with a round scale, the division value of which is 0.02 mm. These calipers are convenient to use for frequent measurements in production. The indicator arrow is clearly visible for quick control of the result; it does not have jumps, unlike digital models. This device is especially convenient to use in the technical control department for measurements of similar standard sizes.
ШЦ-II
Such rulers are used for measuring internal and external dimensions, as well as for marking parts before processing. Therefore, their jaws have attachments made of hard alloy to protect them from rapid wear. The measurement interval of the ShTs-II series of devices is in the range of 0-250 mm and the measurement accuracy is 0.02 mm.
ШЦ-IIIand SCC-III
Large parts are most often measured with this model of instrument, since its measurement accuracy is higher than other models and is 0.02 mm for mechanical instruments, and 0.01 mm for digital instruments.
The largest dimension to measure is 500mm. The jaws in such models are directed downwards and can have a length of up to 300 mm. This makes it possible to measure parts over a wide range.
Special purpose calipers
Let us briefly consider several specialized models of calipers designed for special types works Such devices appear quite rarely in the retail chain.
- SHCT– used for measuring pipes, it is called a pipe caliper.
- SHTSTSV— for measuring internal dimensions, has a digital display.
- SHTSCN– similar to the previous device, used to measure external dimensions.
- SHCCU— a universal digital meter, the kit includes a set of attachments for hard-to-reach measurements: center-to-center distances, pipe walls, external and internal dimensions, etc.
- SHCD– a device for measuring the thickness of brake discs and parts with various protrusions.
- SHTSCP— Vernier calipers are used to measure the tread depth of car tires.
- SHTSTM– calipers designed specifically for measuring center-to-center distances.
Rules for using calipers
- Check the tool. To do this, bring the caliper jaws together and check the accuracy of their closure for the presence of clearance between them.
- Take the tool in right hand, and the measured part in the left hand.
- To measure the external size of a part, it is necessary to spread the lower jaws of the tool and place the part being tested between them. You should be careful when doing this, as the edges of the jaws are sharp and you can get injured if you handle the tool carelessly.
- Squeeze the jaws of the caliper until they come into contact with the part. If the material used to make the part has a soft structure, then strong compression of the jaws will lead to inaccurate measurements. Therefore, the jaws must be squeezed carefully, only until they come into contact with the surface of the part. To move the caliper frame, use thumb hands.
- Check the position of the jaws relative to the part. They must be at an equal distance from the edges of the part; tool distortions are not allowed.
- Secure the screw intended for clamping the movable frame. This allows you to maintain the position of the frame for accurate measurement results. It is advisable to tighten the screw large and index finger, at the same time, with the same hand, hold the instrument in one position so as not to move it to ensure measurement accuracy.
- Put the part aside, and take the fixed caliper without the part to take the measurement results.
- The instrument reading stage is very important, since inaccuracy in measurement can lead to serious consequences in production.
Place the caliper directly in front of your eyes.
1 — Bar scale
2 - 21 divisions
3 — Vernier scale
The figure shows the measurement procedure. On the left are jaws for external measurements with the part being measured, and on the right are scales: vernier and main. Their divisions will determine the measurement result.
First you need to count the number of whole millimeters. To do this, you need to find the division on the rod scale that is closest to the vernier zero. This division is indicated by the first upper red arrow. In our case, this value is 13 mm. This value must be remembered or written down.
Next you need to calculate fractions of a millimeter. To do this, you need to find a division on the vernier scale that coincides with the division on the rod scale. This division in the figure is shown by the second red arrow.
Next, you need to determine the division number in order, for our case it turns out to be 21.
Then you need to multiply this number by the value of the vernier scale division. In our example, the division value is 0.01 mm.
Now it is necessary to calculate the exact value of the measurement determined by the caliper. To do this, you need to add the whole number with fractions of a millimeter. The result is 13.21 mm.
- When finished using the tool, clean it, loosen the screw, close the jaws and put it in the case. If the instrument will be stored for a long time, it is recommended to treat it with an anti-corrosion solution.
If you have a dial or digital caliper, the measurement process becomes much easier, since you don’t need to calculate anything, the finished result will be visible on the display or dial.
A caliper is a universal measuring tool. It is intended for high precision measurements. With its help, you can determine both the external and internal dimensions of the part, the depth of the holes, etc. This is one of the most common tools in the technical field and is easy to use. It is used at a level with things like and . Due to its mechanical structure, the device has virtually no limitations on its service life, since only deformation can bring it out of working condition. Despite its prevalence, many people do not know how to use a caliper.
Measuring with a caliper is used both in industrial and private settings, since the device takes up relatively little space. One of the characteristic features here is the vernier scale, which allows you to make measurements down to tenths of a millimeter. The design features allow you to fix the part being measured, both with inside, and from the outside, to reduce the likelihood of error. To use it, no special training is required and you can start working almost immediately.
The design and principle of operation of a caliper
The instrument got its name due to the presence of a rod on which the main scale is printed. Vernier refers to an additional scale that helps keep track of tenths or hundredths of millimeters if the measurement requires it. The product contains the following basic elements:
- Barbell;
- Moving frame;
- The main scale located on the rod;
- Inner side measuring sponges;
- Outside measuring jaws;
- Depth gauge;
- Vernier;
- The screw that secures the frame.
Some models have a double scale, which can show calculations not only in millimeters, but also in inches. Other parts of the caliper generally remain the same.
As the moving parts move, the part with the control division also moves, which will show the number of millimeters. No matter what you want to measure external dimensions, internal or depth, the movements will be the same, only the control gauge is different. For this there is a depth gauge that will rest on the bottom of the object being measured. For ordinary sizes, the part must be fixed in internal or external jaws. After determining the value on the main scale, you can use the vernier for more accurate readings.
Rules for using calipers
- When measuring a part, you should never allow the caliper jaws to become distorted. After they reach the desired position, they need to be secured with a locking screw to avoid the above troubles.
- While reading the device, you should hold it directly in front of your eyes.
- When using the device, you must follow safety rules, since the ends of the jaws are quite sharp and can cause injury.
- It should be stored in places where sawdust, shavings, water, dust and other negative factors do not enter. However, you should not place it far from the workplace, as it is often used.
- After work and before starting it, the tool should be wiped with a clean rag.
How to measure with a caliper
Before measuring with a caliper, you need to familiarize yourself with the basic rules.
- Measuring external surfaces. In order to obtain data on the external dimensions of the product, it must be fixed in the lower jaws of the tool. To do this, you need to spread it a little more than the workpiece itself, and then bring the jaws together until they stop. After this, you can take readings on the main and additional scales.
- Measuring internal surfaces. For this operation, the tool must be moved to the zero position, and then the jaws for internal measurement must be placed into the workpiece, parallel to the plane to be measured. Next, you should move them all the way, which will help fix them in one position and avoid large errors. This is also suitable for determining the diameter.
- Depth measurement. The main part here is the depth gauge. Measuring with a caliper is carried out by resting the end of the tool on one end of the part and immersing the depth gauge in the other. When it rests or reaches the desired point, you can take readings on the main and additional scales, since the vernier here still remains relevant.
- How to markup. The markings are applied with direct marks from the base edges of the tool, located parallel, or the surface of the workpiece itself. They also make serifs and can draw circles.
photo: external and internal surface measurement with a caliper
photo: measuring depth with calipers
The main problem in understanding how to use a caliper is determining the exact result, as well as using additional functions devices. The situation is most simple and clear with external dimensions, but the principle of removal is almost the same everywhere, therefore, you should learn to handle two scales. The first one, which is also the main one, shows whole fractions of a millimeter. Regardless of whether you use a depth gauge, external or internal jaws, all three parts move according to the measured distance. In order not to lose readings during measurement, when everything reaches the control limit point, the device is fixed.
a) 6.45 mm; b) 1.65 mm
After this, you can remove it from the workpiece and bring it closer to you. The readings remain the same as at the time of measurement. The divisions on the rod are immediately visible and the number of whole millimeters is immediately visible; to determine in more detail, you should use a vernier. It has ten divisions, each of which corresponds to a part of the whole. If the first division coincides with the value of the line on the main scale, then an even value is obtained. If the second division coincides with any line, then 0.1 should be added to the resulting whole value. To the third - 0.2, to the fourth - 0.3 and so on.
There are verniers that show hundredths of millimeters. The measurement principle in them is very similar. The main thing is that the fixing element is always in working order, otherwise it will be impossible to obtain accurate data, since the position of the measuring device will constantly be lost.
How to properly store a tool
Knowing how to use a caliper is not enough, since you need to know the rules for storing and caring for the tool. It is best to store the instrument in the case in which it was supplied. In any case, this should be a dark, dry place where dust, sawdust and other objects do not fall. Considering that all models are made of metal, contact with moisture and condensation accumulation are undesirable. Avoid impacts and scratches, which may deform the instrument and reduce the measurement accuracy. Each time you use, wipe the surface with a dry cloth. Careful handling allows you to use it for many years and even decades.
photo: storing calipers in a case
How to use a caliper: Video
Vernier calipers are a very popular measuring tool. The design of a caliper is quite simple, so almost anyone can use it without any special effort. preliminary preparation. It can be used to measure both external and internal dimensions. various parts, as well as the depth of the holes in them. Despite simple design, this instrument has different accuracy classes and can give readings with an accuracy of 0.1 to 0.01 mm. It received its name based on the main design detail. Thanks to its design, the caliper is rightfully considered one of the most versatile measuring instruments.
Using a caliper, you can measure both the external and internal dimensions of various parts, as well as the depth of the holes in them.
Fundamental design characteristics of a caliper
A vernier tool, in principle, and a caliper in this case, has as its main part a retractable rod with a measuring scale. This scale is divided into divisions of 1 mm, and its total length in the protozoa household model ShTs-1 ranges from 15 to 25 cm. There are also models of larger sizes, but they are used only on industrial enterprises and are much less common. It is by this rod that the maximum value that a given device can measure is determined. specific model caliper.
The ShTsTs digital caliper has a digital display mounted on a movable frame.
A special design feature of it is the presence of such a device as a vernier. This is an auxiliary scale that is movable relative to the main ruler. It helps to correctly determine the number of division shares on this ruler. The divisions on the vernier scale, also known as “vernier”, are a certain fraction smaller than the divisions of the main ruler. There can be 10 of them for a model with an accuracy of up to 0.1 mm, or 20 for models with an accuracy of up to 0.05 mm. The principle of operation of a vernier is based on the fact that it is much easier to determine by eye the coincidence of divisions than the relative location of one division between two others.
If it is necessary to measure external surfaces, such as wire cross-section, large jaws are simply applied on both sides internal surfaces. The wire is clamped between them, and the zero division of the scale of the moving frame gives an indication on the main scale of the rod. Small jaws are shaped like scissor blades, which helps measure the diameter of a pipe or other hole on a scale without additional calculations. They have external working surfaces, having the profile of a sharpened blade, so they can measure such an indicator as the thread pitch.
Components and Applications
The tool consists of a fixed base and retractable fittings. They are made of tool steel. The caliper includes the following components:
- The main rod on which all movable fittings are attached. The main scale is located on it.
- A movable frame with a screw lock and pressed by an internal spring plate. There is a vernier scale on it. It can be applied directly to it, or it can be on a plate secured with screws. This allows you to adjust it relative to the scale on the bar.
- Sponges for measuring external surfaces, or large sponges. One of them is mounted on a fixed rod, and the other on a movable frame. The ends have narrow surfaces, which provide additional measurement possibilities.
- Sponges for measuring internal surfaces, or small sponges. They are located according to the same principle opposite the previous ones along the central axis.
- Ruler for measuring depths. Attached to a movable frame.
The ruler for measuring depth is mounted on a movable frame and moves along a groove made in the plane of the rod. It can also be used to measure internal grooves and shoulder distances. The rod is placed on its end perpendicular to the object being measured. The ruler extends until it rests on the bottom. To measure conical holes, its end has a slight point. After receiving the measurement result, it is recommended to fix the position of the instrument with a locking screw, and only then take readings.
Types of caliper designs and their markings
Along with the simplest mechanical model, the structure of which is discussed above, there are others. They can be divided into 4 main types, having 8 standard sizes. Their designs, as well as their purpose, have some differences. In addition to the double-sided caliper ShTs-1 discussed above, there is a one-sided version ShTsT-1. It has jaws on only one side and a ruler for measuring depths. Although it has a mechanical device, like ShTs-1, the material for its manufacture is hard, high-alloy steel. Such a tool helps to determine the external linear dimensions and depth of holes during abrasive action on the object being measured.
The tool called ШЦ - 2 is equipped with a double-sided design, but the jaws for measuring internal and external surfaces are combined and have a corresponding flat surfaces inside and cylindrical outside. Opposite them are jaws of the same size for measuring external dimensions, which have sharpened edges. This allows you to not only measure, but also mark on the surface of the part being measured. In addition, this model has an auxiliary micrometer feed frame, which allows you to take readings with great accuracy.
The ShTs-3 caliper differs from the previous model only in its one-sided design. Its pair of jaws are designed to measure both internal and external dimensions. This model is designed to measure the largest sizes, so it is also quite large. With what larger sizes measuring device, the greater the resulting measurement error. Therefore, in addition to the designs described above, calipers are divided according to the indicators with which readings are taken.
According to this principle, they are divided into vernier ones, in which the readings are calculated independently based on the movement of the frame, into dial and digital ones. Dials marked ShTsK use the same mechanical principle. On the frame there is a digital scale connected to the rod by a gear transmission. Whole millimeters are read by the position of the edge of the frame, and their fractions are narrower by the dial. This caliper has more high class accuracy than vernier and can be up to 0.01 mm. However, it is very vulnerable to mechanical damage and contamination of the rack from the parts being measured.
The use of calipers is inextricably linked with turning production, installation of various pipeline systems, screw connections and other structures that require increased accuracy.
At the same time, thanks to the design, almost everyone can use it. The ShTsTs digital caliper has a digital display mounted on a movable frame. A reading device is built into the frame, indicating the distance between the measuring jaws. There are buttons on the display that allow you to control them. The accuracy of such a device is 0.01 mm and allows you to measure the most small parts, in particular to control the thread. However, all the disadvantages of electronic devices are inherent in this instrument. Changes in rod parameters due to temperature changes immediately affect the display readings.
In addition to various measuring instruments, a home workshop should also have a caliper, which is often needed where a tape measure or ruler is not suitable.
Below we will look at what such a measuring instrument is, what types are found and how to use it correctly in order to obtain the most accurate measurement data.
Purpose of a caliper
This measuring tool is used mainly to obtain the most accurate data when determining the outer and inner diameters of pipes, the thickness of their walls, to calculate the center distance in holes, and the dimensions of parts cylindrical, wire thickness and metal sheet, as well as other materials of small dimensions and small products.
With such a device it is convenient to measure the depth of grooves, holes and grooves, various recesses with great accuracy in the most hard to reach places. The accuracy of a caliper in measurements reaches tenths and hundredths of a millimeter, which cannot be achieved by such a simple tool as a ruler or tape measure.
The tool, according to GOST 166-89, is made of stainless or carbon steel coated with a chrome-plated composition. Comprises:
- a rigid metal ruler called a rod (hence the name of the tool - caliper);
- measuring protrusions - jaws;
- an auxiliary frame with a vernier scale, otherwise called a vernier, which allows measurements to be made with an accuracy of tenths and hundredths of a millimeter, depending on the type of instrument;
- movable ruler of the depth gauge, rigidly connected to the jaws.
The vernier caliper scale can have different lengths and number of divisions. 10 divisions on the vernier scale make it possible to measure with an accuracy of up to 0.1 mm, 20 divisions provide a measurement accuracy of up to 0.05 mm:
Sponges can be upper and lower. On the surface of the lower - indicated minimum size measured parts. The ends of the lower jaws are made in the form of rectangles. The upper ones are pointed and beveled vertically, which allows them to mark on any materials and parts, without the use of other marking devices (i.e., directly with the sponges, you can draw a line exactly in size due to the sharp ends).
Using the upper jaws, the internal dimensions of holes, pipe diameters, grooves, and various recesses are measured. To measure external parameters, lower jaws are used. To measure length deep holes a depth gauge ruler is used, which extends from the main rod:
To fix the movable frame with a vernier scale on the ruler, there is a special fastening screw. Some caliper models are equipped with a round scale and a movable frame, the scale of which is designed to take measurements in inches. At the same time, the vernier scale of such a device allows measurements with an accuracy of up to 0.128 inches.
Types of calipers and technical characteristics
The classification of such measuring instruments is carried out according to several parameters - the method of taking readings, the type of scale, the location of the jaws. All these differences are reflected in the markings of the device.
U different types The following types of scales can be used for taking measurement readings:
- vernier scale;
- scale located on the dial;
- using a scoreboard with a digital indicator.
According to their design, calipers are divided into the following types:
- Single-sided tools made of carbide steel and marked ШЦТ.
- Mechanical models with one- or two-sided arrangement of jaws, marked as ШЦ-I, ШЦ-II, ШЦ-III, measurements on which can be taken using a vernier scale.
- A device equipped with a circular scale is marked ShIK or ShTsK and allows for more accurate measurements than devices with a vernier scale. The dial scale shows fractional readings, while the bar itself shows whole numbers.
- The latest generation electronic caliper with a digital display showing the distance between the internal surfaces of the jaws is marked SCC and can work in symbiosis with a PC. This is the best device that allows you to quickly, without unnecessary calculations, see measurement data, which is carried out with high accuracy up to 0.01 mm.
The ShTs-II tool differs from the ShTs-I model in that it has an additional frame equipped with a locking screw and connected to the main frame. A fixed additional frame allows you to bring the ends of the jaws in for more accurate measurement of the internal dimensions of the holes.
The ShTs-III device differs from the ShTs-II model in that it does not have one pair of upper marking jaws. Used for measuring large parts.
How to use a caliper correctly
Before using the tool, you must check it for serviceability and accuracy. To do this, you need to inspect it and remove any existing dirt from all parts. It is also necessary to check whether the zero marks on the main scale and the vernier scale coincide when the lower jaws are tightly connected.
It is best to fix the part being measured in a stationary state, but you can also hold it in your left hand, the main thing is to prevent it from moving during the measurement process. If you need to measure the external dimensions of any part, you need to spread the jaws and tightly cover the object being measured with them. In this case, the part must be in correct position, without distortion and should not move. The next step is to fix the part in the caliper by screwing in the mounting screw, without excessive force. Only after this can you start reading the readings.
When using the ShTsTs device, you do not need to calculate the dimensions of the part being measured; all this is shown on the display. It is also not difficult to take measurements when working with the ShCK device. Integer numbers on the bar are indicated by the edge of the movable frame; hundredths or tenths of a millimeter are indicated by a dial scale.
But with a mechanical instrument ШЦ-I, ШЦ-II and ШЦ-III it will be necessary to compare the values of the main scale and the vernier scale. First, the size is determined in whole numbers, i.e., the reading on the main scale, which is determined by the position of the first mark of the vernier scale. Then, depending on the type of caliper, the size is determined in tenths or hundredths of a millimeter.
Total, Measurement algorithm:
- We look at the top scale to see how many whole millimeters fit.
- On the lower scale we look at which division coincides most closely with the division on the upper scale (as if it turns into one line) - these are tenths and hundredths of a millimeter.
Let's look at the picture to see how the measurement of 28.55 millimeters is obtained:
When using the tool, you should take into account the error of the caliper, which may arise due to improper storage, mechanical damage, contamination of the tool, temperature state of the part being measured. Optimal temperature For measurements this device has a range of 10–40 degrees above zero. To obtain the most reliable measurement data when using a caliper, it is recommended to take several measurements and calculate the arithmetic average. Upon completion of measurements, the device must be wiped dry and stored in a case.
This is where the article ends. Today we learned what a caliper is, what types it comes in and how to take measurements with it.
