A micrometer is what? The device and the price of a micrometer. How is the micrometer measured?

In some cases, during the measurement of objects, a high accuracy of results is required, which can not be obtained with a conventional ruler. In such situations, special micrometric tools are used. What is a micrometer and how to use it is described in this article.

What is a micrometer?

It is a tool designed to accurately measure small parts. The micrometer allows you to determine the thickness, depth, external and internal diameters of products. To perform these measurements, micrometric depth gauges, internal gauges, and other micrometers of different designs are used.

All varieties of this measuring tool work on the same principle: the use of mutual movement of the nut and screw. Among all micrometric mechanisms, the most common are micrometers.

A micrometer is a small metal tool that consists of a screw, a latch and a tip. It allows you to measure objects with a high degree of accuracy. The error of the tool is very small and ranges from 2 to 9 μm. It should be noted that 0.1 mm = 100 μm, that is, 1 μm is a millionth part of a millimeter. The maximum displacement of the screw is 25 mm. This length contributes to the maximum measurement accuracy. If the length of the micrometer screw was larger, the results of the measurements would not correspond to reality. Some models of micrometers allow measuring products with sizes up to 100 mm due to the use of replaceable heels.

There are strict technical requirements that a micrometer must meet. GOST specifies that all models of the measuring instrument should have an accuracy of 0.01 mm. Also, according to standards, micrometers can be produced with such measurement limits: 0-25, 25-50, 50-75, 75-100 and so on up to 300 mm, and then 300-400, 400-500, 500-600 mm.

History of occurrence

Mankind has known for many centuries what a micrometer is. According to historical facts, the screw measuring mechanism began to be used as early as the 16th century in the sighting mechanisms of artillery weapons. A little later the instrument was used in geodetic devices. But he did not give the required accuracy of the results. And it was only in 1867 that American engineers created a micrometer that allows obtaining qualitative measurements.

Types of micrometers

The micrometer is the most versatile measuring device. The ease and ease of use made it virtually indispensable in many industrial areas. Due to the variety of measuring objects, the following types of micrometers are produced:

• Sheet - designed to measure the thickness of flat sheets made of metal or other material;
• Lever - differ from other micrometers by the presence of a lever-toothed head, which allows high-precision manufacture of complex products or their repair;
• Smooth - devices of this type are equipped with a clamp and ratchet, which allow measuring objects with a smooth surface; Smooth micrometers are the most common and are used in almost all industrial sectors;
• Universal - designed to take internal and external dimensions of different parts;
• Pipe - used to measure the pipe walls;
• Threaded and wire - enable to measure the thinnest products, for example, optical cable ;
• Digital - measurement by a micrometer of this type provides additional advantages: data accounting and the possibility of instant processing on a computer.

As for production, two types of micrometers are used to the greatest extent - mechanical and digital. Let us dwell on them in more detail.

Mechanical micrometers

A mechanical-type micrometer is a traditional measuring instrument and is widely used in various branches of the national economy, despite the availability of a more sophisticated electronic analogue.

The device of the micrometer mechanical consists of two parts:

• Handles (ratchet, stem and drum);
• A semi-circle recess with a support post for fixing the measured object.

To measure a part, you need to follow this pattern: first you need to place the object on the support post and screw the micrometer screw. After this, you need to scroll the ratchet to adjust the metering. When it starts to scroll, it means that it has already been frozen. The last step is to remove the values from the scale on the drum and stem.

There are models of micrometers that are equipped with a locking mechanism. It allows you to hold the ratchet in place so that the fixed value does not go off until the result is recorded in a special book or magazine.

Micrometer digital

The electronic device is an improved form of a simple mechanical micrometer. It is more modern and convenient to use. Thus, a digital micrometer allows obtaining measurements with an accuracy of 1 μm and an error of up to 0.1 μm. Many models have built-in calibration.

Externally, the electronic device differs from the mechanical model by the presence of a digital display. The user can select any of the possible calculation systems. For example, inches or millimeters. Also, the scoreboard displays other important information. So, at any time you can view the level of battery power.

To reduce energy costs, the device can be programmed for automatic shutdown. Mostly this happens after 5 minutes of inactivity.

There are technical requirements that a digital micrometer must meet. GOST stands for division scale, permissible errors and other important features of the device.

How to use the device

1. Tool check. Immediately after purchase, the device should be checked for suitability and absence of defects. If the micrometer is working, then you need to adjust the scale. For this purpose, a special key is used in conjunction with the tool. If everything is done correctly, the display of the digital device when the measurement planes without the part is closed should show 0. In the mechanical micrometer, the drum should close the stem, and the zero value of the drum scale must coincide with the longitudinal stroke on the stem. Such manipulations are desirable to be done periodically, in order to be able to detect faults in time and adjust the micrometer. This will in the future exclude incorrect measurements.
2. Fixing the part. This stage is very responsible and requires adherence to important recommendations. So, first you should place the object between the measuring planes and simple rotations of the drum to bring the screw to the part. After a short rotation, an emphasis should be felt. Then you should move on the handle and continue to twist the ratchet until three clicks sound. This will be a signal that the part is securely fixed.
3. Measurement with a micrometer. After fixing, the digital instrument will show the measurement result on the display panel. As for the mechanical device, it will take a little trouble. The result should be read from large digits and end up small. First you need to look at the marks of the stem. There are two scales on it. The upper divisions denote 0.5 mm, and the lower ones - 1 mm.

Industrial applications

Micrometric instruments are indispensable in modern industry. This is especially true for industries that work with small parts. So, practically all instrument-making enterprises use a micrometer. This allows you to produce parts with a high degree of accuracy. Also, the measuring device is used in the jewelry industry to measure the size of the stones.

It is impossible to do without a micrometer at many stages of the automotive industry. That is, the micrometric tool is used wherever production is associated with small and medium details.

Cost of micrometer

Today, a wide variety of micrometers is on the market. The wide choice of the tool is explained by the active growing demand for the micrometer. The price for different models of the device can vary significantly. It depends on the functionality, strength of the material, reliability. A great influence on the cost of the tool is provided by the manufacturer. As a rule, the micrometer of a well-known brand costs much more than the usual Chinese. In this case, the buyer himself decides what is more important - to save on the device or to have a high-quality measuring mechanism. So, the price for a digital smooth micrometer is in the range of 90-200 euros. A conventional mechanical device can be bought for only 19 euros. More complex models with integrated digital displays, levers, replaceable measuring elements are much more expensive.

Important recommendations

1. Before using the micrometer, you should hold it and the measuring object for 3 hours in the same temperature mode.
2. The markings on the scale in different micrometers may differ. Therefore, before counting the measurements, you should read the instructions and carefully understand the values of the divisions plotted.

Now you know what a mic is, and you can use it to practice.