How to use theodolite

Every builder should have a theodolite on hand. How to use theodolite correctly? First of all, you should know that it is designed to measure contour lines and verticals. It is often used in combination with the level.

Various theodolites and levels

Theodolites and levels are used to measure the contour lines and verticals of various surfaces.

The complex electronic “stuffing” allowed the theodolite to compete with similar construction devices. If you compare it with a tachometer, it gives the same accurate readings, but it costs much less. Of course, it is difficult to carry out complex measurements in the absence of computing equipment and a knowledge base, but for work with verticals and contours this is not required. Therefore, even a novice can work with a theodolite.

What is a theodolite?

Before starting work, you should be familiar with the device tool. The instrument package may consist of a landmark-compass, optical rangefinder nozzles, reticle and other. These are not obligatory adaptations, but it is better that they were in a set. In the case of specialized works, tools of a more narrow focus are used:

  • surveying - used in the work in the mines, for the extraction of coal;
  • astronomical - the scope of application is astronomy, ocular micrometers are also supplied with them;
  • gyroscopic - used in work related to the measurement of angles, and help determine the direction of the meridian.
Theodolite Scheme

Theodolite scheme.

Depending on the area in which the theodolite will be used, it may have some additions to the configuration.

The main units of the device are:

  1. The body, on which are fixed horizontal and vertical reading circles.
  2. A support-trayer, on the basis of which there are 3 screws (used for adjusting the position) and a circular level.
  3. Pipe for observation.
  4. Screws for pointing and fixing the device.
  5. Plumb.
  6. Microscope for counts.
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How to use a theodolite?

This tool, before starting to make calculations, must be properly installed. The reliability of mounting directly affects the accuracy of readings. The preparatory stage includes centering the instrument, adjusting the horizontal and installing the observation tube.

Theodolite Tripod

To reliably and correctly establish a theodolite, use a special geodetic tripod.

Centering is performed in order to combine the limb of the horizontal circle and the plumb line, which, in turn, passes through the point of the instrument. The second point is designed to ensure that the axis of rotation of steel in a sheer state. It is at that moment that the limb assumes a horizontal state. As for the leveling, at first it is done “by eye” during the tripod mounting. After this adjustment is made with screws and a cylindrical level, which should already be as accurate as possible.

Immediately it should be noted that it will be difficult to use the theodolite if there are no skills to communicate with such equipment. Even after reading the manual for using the device, it will be difficult to achieve accurate results. Therefore, it is recommended to initially take internship courses to familiarize yourself with this tool.

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How to measure vertical angles?

To work with corners professional builders use theodolite. The procedure can be done independently.

Theodolite on a tripod

For proper operation, the theodolite must be firmly mounted on a tripod.

To do this, perform a series of simple operations. First of all, the theodolite is securely fixed in a tripod, which should stand firmly on the ground, without any wobbling. After installation, you should decide on two points on the object that is being measured. With the help of the screw, the observation tube is directed to the marks.

Next, you need to combine the vertical thread of the pipe with one of the selected marks and read the indicators, which will show the horizontal circle. So that the pipe can move, the screws slightly loosen. The observation element should be moved clockwise until the second mark falls under observation. After that, the second readings are taken.

You can also use another method - circular. It is used in cases where the measurement work is carried out from a single point. Then you need:

  1. Install a theodolite on the job site and level it. It should be noted that the location of the limb should be as close as possible to 0.
  2. Next is the rotation of the alidade until the zero stroke of the microscope becomes one level with the zero stroke of the limb. After that, the pipe is directed to the marks, for which the screws are loosened slightly. As soon as measurements are made, the locking screw is tightened and calculations are made.

Horizontal angles are measured without regard to the position of the instrument. In order to carry them out, the observation tube should be gradually led to two elevations, which are the basis for measurements. At the same time there is a parallel reading in a horizontal circle. To determine the measure of the object, it is necessary to work with the basis of the difference of reference.

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What are the varieties of theodolites?


Electrotheodolite is the most accurate type of instrument.

Before you purchase and start using a theodolite, you should be familiar with the models presented in the current market.

There are several parameters by which devices are classified: accuracy, design, limb counting method, and purpose.

  1. Accuracy. There are three groups of this feature:
  • technical, when SKO goes more than 20 seconds;
  • accurate when the standard deviation varies from 2 to 15 seconds;
  • high-precision when the standard deviation has less than a second.
  1. Design.

There are two of them: simple and repetitive. In the first case, the device has an alidade that is rigidly attached to a vertical cylindrical axis. In the second variant, the alidade and limb can rotate not only together, but also independently from each other. This design leads to the fact that the angle is measured several times. From what, in fact, went the name of the device.

By the way, simple models have several more subspecies:

  1. Gyrotheodolite This device is used in the field of topography, surveyor, geodesy and other similar areas. With it, it is possible to determine the azimuth.
  2. Photo or kinoteodolit. In this embodiment, there is a photo or movie camera.
  3. Electrotheodolite It is by far the most modern model. With the help of electronics, not only calculations are made, but also their memorization. The convenience of this technique is that it eliminates even the slightest error, moreover it makes it possible to carry out night work.
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Ways to work with the tool

Theodolite at a construction site

Theodolite is used in various types of work in the fields of construction and geodesy.

There are two main ways to obtain values: polar and with the help of alignments with perpendiculars.

Polar. As described above, this method is based on two points with already prepared values. The measurement comes from the second mark on the first. After that, the distance between the points is measured using a tape measure or the same rangefinder. At the second point, the indicators of angles with respect to each mark of the contour will be obtained. The last point is tying the traverse to each mark.

Due to the fact that the marks are located in the same coordinate system, this site is possible to produce in a closed, that is, in it the sum of all known angles will be a multiple of 360 degrees. Since the errors will still be present, then there will be a discrepancy, and it, in turn, can be compared with the allowable one. If the received figures are included in the tolerance, then the error is evenly spread to the sides of the site.

The second method can often be found in the performance of center works. This option involves the laying off of right angles on the ground, with the tool will gradually pass each point.

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Use of the tool in the construction sphere

The convenience of theodolite is that it is not whimsical to the conditions of operation.

This is one of the reasons for its popularity in various industries. Depending on the need, you can use electronic or mechanical tools. If it is very important to have the most accurate readings, then it is best to use those devices that use a laser.

Builder with theodolite

At the construction site theodolite is needed to control the flatness of the building.

Why is a theodolite used in construction? Because this device helps to control the vertical and horizontal angles, which is important in the construction of buildings, especially with regard to high-rise buildings. There is no foundation yet, and the theodolite should already be in the hands of the builder. With this tool it is possible to calculate the angle of slope of the terrain. If you don’t think about this moment, then the probability of a building skewing is very high.

Further, the theodolite is used by the following floors. This will save from the construction of the "leaning tower". Moreover, such a device helps to significantly save time on manual calculations and measurements. To navigate the results, the master would do well to know the basics of geometry.

If without such a device, you can still somehow manage in private construction (although this is not recommended), then for developers of multi-storey buildings it is simply irreplaceable. After all, not only will the reliability and quality of the structure depend on this, so the theodolite also helps to make a more accurate estimate. Therefore, if a team of builders is hired, it will be useful to familiarize yourself with their tools, which can tell a lot.

Qualified specialists are always responsible for their work, which is impossible to do without the appropriate tools and materials.

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