Performing most types of construction and installation work is impossible without the use of a special tool - a goniometer. As the name suggests, this device is used to measure the angles of structures. The most popular at the moment are mechanical tools of this variety. Such goniometers are inexpensive, easy to use, and measurements using them 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, such as, for example, pyramids, would be simply impossible without a goniometer.
The design of this simple device has not changed much over the past centuries. Modern goniometers look exactly the same as those used by the ancient engineers of Egypt. The only thing in our time forother materials are used in the manufacture of such tools. Of course, the scope of modern goniometers is much wider.
Classification by purpose
There are many types of this popular instrument. Goniometers are classified mainly according to their purpose. Modern manufacturers produce the following versions of this tool:
- Building. Tools of this group are usually used for marking or mounting operations. The construction mechanical goniometer can also be used in the development of drawings for projects of buildings and structures.
- Carpentry. Such tools are simply indispensable when performing various kinds of work with wooden blanks.
- Mountain. Used in mine surveying.
- Seaworthy. Used to determine geographic latitude.
- Plumbing. Such tools are used when performing work of the corresponding specialization. A metalwork mechanical goniometer usually has a fairly high degree of measurement accuracy.
- Educational. Schoolchildren use these tools in class and when doing homework.
- Artillery. This type of instrument is also highly accurate. Goniometers of this type are used when installing artillery pieces.
- Universal. This group of devices can be used to measure angles in a variety of applications.
Types by way of use
All mechanical tools on the market today can also be divided into groups according to such characteristics as the size and type of error. In addition, such devices are classified by scope. A modern mechanical goniometer can be used:
- For measuring outside corners. Such models are marked with the letters UM.
- For measuring internal angles (IN).
Design Features
The unit of measurement of any angle, as you know, is a degree - 1/360 of the diameter of a circle. He is the step of the goniometer. Degrees, in turn, are divided into minutes and seconds. A common structural element 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 applied. The latter is movably fixed on a special ruler, which serves as the starting point for measurement. Very often, instead of a ruler, a square is included in the design of such tools. It is fixed on the base plate. You can fix the measurement result in such devices using a special screw.
Mechanical pendulum goniometers additionally have a special structural element that assumes a vertical position when the angle of inclination of the measured part changes. Such tools are more convenient to use than conventional ones. They are used most often when working with overall products. For example, they measure the actual angleslocation of units and mechanisms of agricultural machinery.
Goniometers are made most often from tool steel. This material is durable and damage resistant. A steel mechanical protractor serves for a very long time. In some cases, tools of this variety can also be made of wood or plastic. Such models are most often used when performing various kinds of repair work indoors (for example, when installing wall panels or installing skirting boards). Sometimes devices of this type are also made of lightweight aluminum.
Goniometer with vernier
This is one of the most convenient types of tool. The vernier is called the auxiliary scale mounted on the goniometer. This small additional element is fixed above the upper edge of the arcuate base and remains motionless during operation. It serves to more accurately determine the number of division shares on the main scale. The principle of operation of the vernier is based on the fact that the human eye notices the coincidence of divisions much more accurately than the location of one of them between the others. A mechanical goniometer, supplemented with such an element, of course, is much more convenient to use than a conventional one. In addition, the measurements themselves using it can be made much better.
Instructions for use
The question of how to measure angles with a mechanical protractor is quite simple. Using such a device, of course, is more difficult than using an electronic version. However, learn toyou can still work pretty fast. Measurements when using mechanical devices are made by choosing various combinations of the position of their elements. For example, external corners when using the Semenov universal tool are checked as follows:
- The square is pressed against one of the sides of the corner of the product.
- The scale of the arcuate base is applied to the other.
- Carefully check the junction of the tool and the sides of the corner of the product for gaps.
- Fix the instrument with a screw on the object to be measured.
- Look at what value on the scale coincides with the edge of the square.
Even easier to measure the angle between converging or divergent opposite sides of a workpiece. In this case, you can also use the protractor mechanical design Semenov. To measure, one of the sides is simply attached to the horizontal bar of the tool on which the square is fixed, and to the other - the scale of the arcuate base.
Reviews about goniometers "Quadrant Fit"
The most popular models of such devices, in addition to Semenov's instrument, are "Quadrant Fit" and Mitutoyo. The first brand of tools is usually made of plastic. Its main advantages include rather high measurement accuracy and good build quality. As the owners of these goniometers note, all their elements are fastened securely and do not hang out. The disadvantages of consumers include onlysome fragility of the material used for their manufacture. However, on sale there are also models "Quadrant Fit Profi" made of aluminum. The main distinguishing feature of this brand of goniometers is the presence of an elongated ruler. They can also be used to measure dimensional products. Not too high a cost - this is also what this mechanical goniometer has earned 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
Mitutoyo manufactures both electronic and mechanical goniometers. The latter are also referred to as fairly accurate and high quality. This brand is produced in Japan and is, of course, more expensive than the Chinese Quadrant Fit products. Mitutoyo goniometers are highly praised for the fact that they are equipped with a special magnifying glass over the sector scale. Of course, this little addition makes measurements much easier.
Malki "Zubr"
Thus, both brands described above, having a classic design, are rated by consumers as quite worthy. However, sometimes this type of tool is needed to perform the simplest jobs. In this case, a special kind of protractor is usually used - malki. Their main distinguishing feature is the simplicity of design.
Forperforming such work as measuring the corners of an apartment when installing skirting boards, for example, mechanical protractors "Zubr", quite popular with consumers, are often used. They consist of only two elements - a metal bar and a ruler with a scale movably fixed on it.
