Protractor mechanical: a review, description, instructions for use, types and reviews

Implementation of most types of construction and installation work is impossible without the use of a special tool - a protractor. As already can be judged by the name, this device is used to measure the angles of structures. The most popular at the moment are the mechanical tools of this variety. Such goniometers are inexpensive, they are easy to use, and measurements with their use can be made quite accurate.

Tool history

The mechanical goniometer was invented a very long time ago. Along with the ruler, it is one of the most ancient instruments on earth. Scientists believe that it first appeared in Egypt and Babylon. After all, the construction of such grandiose structures, as, for example, the pyramids, without a protractor would be simply impossible.

The design of this simple device has hardly changed over the past century. Modern goniometers look exactly like those used by the ancient Egyptian engineers. The only thing in our time for the manufacture of such tools are used other materials. Of course, the scope of modern goniometers is much wider.

Classification according to purpose

There are many types of this popular tool. Graduates are classified mainly for the purpose. Modern manufacturers produce the following versions of this tool:

1. Construction. The tools of this group are usually used for performing marking or erection operations. The goniometer mechanical construction can also be used in the development of drawings of buildings and structures.

2. Carpentry. Such tools are simply indispensable in the performance of various kinds of work with wood blanks.

3. Mountain. Used in surveying surveys.

4. Nautical. Are used to determine the geographical latitude.

5. Locksmiths. Such tools are used when performing the work of the corresponding specialization. The mechanical mechanic gauger usually has a fairly high degree of measurement accuracy.

6. Educational. These tools are used by schoolchildren in class and when doing homework.

7. Artillery. This kind of tools is also very accurate. Goniometers of this type are used for the installation of artillery pieces.

8. Universal. This group of devices can be used to measure angles in a variety of jobs.

Kinds by the way of use

Divide into groups all the existing mechanical tools on the market can also by such signs as size and type of error. In addition, such devices are classified in terms of scope. Use modern goniometer mechanical can:

1. To measure external angles. Such models are marked with the letters UM.

2. For measuring internal angles (UH).

Design Features

The unit of measurement of any angle, as is known, is, degree - 1/360 of the diameter of the circle. He is the step of the protractor. Degrees, in turn, are divided into minutes and seconds. The common element of the construction of all instruments of this type is the base in the form of a movable arc, on which a scale with degrees and minutes is plotted. The latter is movably fixed on a special ruler serving as a starting point in the measurement. Very often in the construction of such tools instead of the ruler is a gon. It is fixed on the support bar. The obtained result of measurement in such devices can be fixed with a special screw.

Mechanical gantry mechanical pendulums additionally have a special design element that assumes a vertical position when the angle of inclination of the measured part is changed. Such tools are more convenient to use than conventional ones. They are used most often when working with dimensional products. For example, with their help, the actual angles of the location of the nodes and mechanisms of agricultural machinery are measured.

Graduates are most often made of tool steel. This material is durable and resistant to damage. Serves steel goniometer mechanical for a very long time. In some cases, instruments of this variety can also be made of wood or plastic. Such models are most often used in performing various kinds of repair work inside the premises (for example, when installing wall panels or installing skirting boards). Sometimes devices of this type are also made of light aluminum.

Protractor with vernier

This is one of the most convenient types of tools. Nonius is the auxiliary scale that is mounted on the protractor. This small additional element fixes above the upper edge of the arcuate base and remains stationary during operation. It serves to more accurately determine the number of fractions on the main scale. The principle of the nonius action is based on the fact that the human eye much more accurately notices the coincidence of divisions, than the arrangement of one of them between the others. The mechanical gyro, supplemented with such an element, is, of course, much more convenient to use than the usual one. In addition, the measurements with its use can be made much better.

Instructions for use

The question of how to measure the angles with a mechanical goniometer is quite simple. Of course, using such a device is more complicated than an electronic version. However, you can still learn how to work quickly. Measurements using mechanical devices are made by selecting different combinations of the positions of their elements. For example, external angles when using a universal tool Semenov check this:

1. The square is pressed against one side of the corner of the product.

2. To the other, a scale of an arcuate base is applied.

3. Carefully check the place of abutment of the tool and the sides of the corner of the product for the absence of gaps.

4. Fix the screw tool on the measured object.

5. Look at what value on the scale coincides with the edge of the square.

It is even easier to measure the angle between converging or diverging opposite sides of the workpiece. In this case, it is also possible to use a goniometer of the mechanical design of Semenov. To measure to one of the sides, simply place the horizontal bar of the instrument on which the square is fixed, and to the other - the scale of the arcuate base.

Reviews about the goniometer "Quadrant Fit"

The most popular models of such devices, in addition to the tool of Semenov, consumers include "Quadrant Fit" and Mitutoyo. The first brand of tools is usually made of plastic. To its main advantages include quite a high accuracy of measurement and a good build quality. As the owners of these goniometers note, all of their elements are fastened securely and do not hang out. To the disadvantages, consumers attribute only a certain flicker of the material used for their manufacture. However, on the market there are also models "Quadrant Fit Profi" from aluminum. The main distinguishing feature of this model's goniometer is the availability of an elongated ruler. You can apply them, including for measuring overall products. Not too high cost is also something for which this mechanical grade has gained popularity among consumers. The price for plastic models "Quadrant Fit", depending on the supplier, ranges from 150-250 rubles. Models "Profi" cost 400-500 rubles.

Mitutoyo brand tools: reviews

The company Mitutoyo produces both electronic and mechanical goniometers. The latter are also spoken of as quite accurate and qualitative. This brand is produced in Japan and is, of course, more expensive than Chinese products "Quadrant Fit". The Mitutoyo protractors are very praised for being equipped with a special magnifying glass over the sector scale. Of course, this small addition greatly facilitates the measurement.

Malki "Zubr"

Thus, both brands described above, having a classical design, are estimated by consumers as quite worthy. However, sometimes an instrument of this type is needed to perform the simplest work. In this case, a special kind of goniometer is usually used - malki. Their main distinguishing feature is the simplicity of the design.

To perform such work as measuring the corners of the apartment when installing skirting boards, often used, for example, are quite popular with consumers mechanical goniometers "Zubr". They consist of only two elements - a metal bar and a ruler with a scale movably fixed on it.