Precision is very important in engineering and construction work. And to make complex constructions, as they say, "by eye" in such cases is unacceptable. There are a large number of geodetic instruments that allow you to correctly perform measurements and calculations. For example, levels, measuring tapes, tachometers and other devices.
Among them, theodolite should be distinguished. This is the main high-frequency device that ensures the correct operation of surveyors. Theodolites are optical and electronic. They take angle surveys, measuring both horizontal and vertical angles.
Applications
This geodetic device is used in the following areas:
- when you need to build topographic maps and plans or a whole network of geodetic points on a plot of land formed by triangles;
- when you need to determine the location of the points on the site in relation to each other;
- for construction work, for example, when you need to fix the horizontal or vertical construction structures (piles, columns, etc.);
Working with a theodolite is not difficult. To perform complex calculations and measurements, you need to purchasecertain skills.
Device classification
Theodolites have several varieties. This is:
- Optical theodolites. Devices of this type are the most common. They are accurate and reliable for use in the field. Theodolites of this type are popular among surveyors. They have a number of advantages over electronic counterparts: they do not need batteries to work and they are easy to use. Optical theodolites can perform work in a fairly wide temperature range, even at negative temperatures. Theodolites of this type have minimal capabilities. Reports are made on a goniometric scale. If the tool does not have internal memory, then a field book will need to be provided in which all data will be recorded.
- Laser theodolites are also not difficult to operate. Such a device uses a laser beam, which serves as an accurate pointer. The device combines the functions of two devices - a sight and a high-frequency electronic instrument for measurements. The device is equipped with a powerful processor that performs all calculations and displays the results on the display of the device. The ease of use and convenience of such a theodolite is obvious.
- Digital theodolites do not use vertical and horizontal circles containing degree markings. Instead, barcode discs are used. The device performs measurements automatically. The design of such a device contains a storage device. Theodolite stores data in the internalmemory. Digital theodolites should not be used in harsh climates or low temperatures as these devices contain power supplies and an LCD display.
- Phototheodolites and cinetheodolites belong to the category of instruments with a specific purpose. The design of the former combines a theodolite and a camera that determines topographic coordinates. The main purpose of cinema theodolites is to fix the trajectory of moving objects both on the ground and in the air.
Design of the device
By their design, theodolites are divided into the following types:
- Simple. In theodolite schemes, the alidade and limbus rotate independently.
- Repetitive. The rotation of the limbus and alidade can occur both separately and together.
Theodolites according to their accuracy are divided into:
- Technical, having an error of 15 - 60 arc seconds.
- Accurate to less than 10 seconds.
- High precision. Allows you to perform measurements with an error of up to 1 arc second.
Shared device
Theodolite contains the following elements:
- Sighting tube. It has some magnification. This part is fixed on two columns that are mounted on a tribrach.
- Countdown mechanisms. These include a vertical and horizontal circle (limb). The first is in the column, and the second at the base of the device.
- Line or bar microscope. This theodolite reading device is used inmechanical tools. In the first one, the reading is performed by the index stroke, and in the second, by the scale. The microscope is designed to read readings from limbs.
- Alidade. It is a rotary ruler, which has a rigid connection with the body of the limb. Contains a reference mechanism - verniers.
- Fixing and leading screws. During tuning and adjustment, these screws give the mechanisms of the device a gentle movement.
- Center This built-in optical plummet provides precise centering over a point.
- Tripod. This element is used when performing work on a specific area. A theodolite is installed on it.
How does the device work
Mechanical theodolite works according to the following principle. The user observes images of various points of the structure through the eyepiece of a telescope. When the sight is aimed at the observed point, both the vertical and horizontal angles are fixed in the eyepiece of the microscope, which has a dashed or scale marking. The first is the tilt angle and the second is the heading angle.
The specialist sequentially directs the pipe to the control points of the structure, measures the angles, and then records these indicators in the log. All this is done when an optical theodolite is used. Angle measurements made by a surveyor play an important role. They allow you to find out how well the project is running.
When using electronic devices in the work, there is no need for visual fixation of corners. After all, electronic sensors for horizontal andvertical circles automatically transfer all data to the LCD display of the device in a digital form familiar to humans. Also, all data is stored in the device memory. The use of electronic theodolites provides an increase in the productivity of a specialist and the elimination of errors associated with incorrect visual reading of the available readings in the case of measuring angles on an optical model.
How to work with a theodolite?
How to determine whether the required point of the measuring angle has been fixed correctly? All theodolites are equipped with levels. During the installation process, they must be accurately set. By adjusting the screws, you can get the required level. The accuracy of the center of the limb is set by a plumb line or an optical plummet. When you know what elements the device consists of, you can start working with the theodolite.
Installation and setup of the device
How to use this tool? First you need to install the device on a tripod. Then you need to decide on two reference points on which the telescope of the instrument will be aimed. First, it is directed to the first point. Next, the device is fixed and measured by means of a vertical thread. Then a horizontal circle is counted. All data must be logged, then uncommitted. Next, you need to track the second point. To do this, turn the theodolite clockwise. At the next stage, the pipe is rotated through the zenith.
Next, you need to change the position of the circle and point the pipe at the point. If there are slight discrepancies in the measurements, then the average value will be correct. During the measurement, the dial should have a value of zero or close to it. The rotation of the alidade must be stopped at the moment when the strokes coincide with zero values on the limb and microscope. All the above measurements are taken in a circle.
Instrument selection
Before choosing a device, you should decide on the type of work that will be performed on the theodolite. In most cases, the simplest device that has average characteristics will do. Typically, these devices are inexpensive. When choosing a theodolite device, you should not pay much attention to parameters such as data transfer and internal memory, since they have no functional use.
Theodolite instruction manual
Each theodolite comes standard with instructions for use. The user manual describes the sequence of work on the device. Using this little book, you can deal with theodolite without outside help. The user manual is also a warranty card and a technical passport of the device. The average price of an electronic theodolite is 50-70 thousand rubles.
How does a theodolite work?
The instructions for the theodolite contain a minimum of information about the device. It includes the following data:
- key specifications;
- scope;
- assignment of buttons;
- how to properly install the instrument and prepare for measurement;
- howuse appliance;
- targeting;
- how to check and adjust the instrument;
- caring for your device.
The paper manual is compact and versatile, which is a big advantage. It doesn't take up much space and you can take it with you. With such an instruction, the LCD display will not freeze and charging will not sit down. From it at any time you can find the necessary information, even if you are in the field, at a construction site or a quarry.
The instructions for the theodolite device have all the information about the instrument that will help you set up and verify.
Domestic theodolite
Theodolite 4T30P is the most popular domestic surveying device. It is manufactured by the Ural Optical and Mechanical Plant. This theodolite belongs to the category of technical precision instruments. Theodolite 4t30p has the following advantages:
- readings are taken using a scale microscope;
- you can use the tripod method. In this case, use a removable stand with a built-in optical plummet;
- contains a direct image spotting scope;
- shift of the dial is performed by rotating a special screw of the device;
- removable tribrach present;
- the device can be used in different climatic regions;
- light weight;
- small dimensions of the device.
Theodolite is successfully used in the following areas:
- agriculture;
- geodesy;
- landscape design;
- geology;
- forestry.
This theodolite instrument is often used in harsh field conditions. The price of a theodolite is approximately 50-60 thousand rubles.
Thus, the choice of theodolite is up to you, which directly depends on the scope of the work.
