How to use the theodolite - a few words about the device
Some devices include a guide-bus, optical rangefinders, sight marks and some other additional devices. At this time, specialized theodolites are also used:
- surveying - for work in coal drifts;
- astronomical - completed with an ocular micrometer;
- gyroscopic theodolite is designed to measure angles and determine the direction of the meridian.
Regardless of the configuration and purpose, any theodolite consists of the following main components:
- body, with fixed horizontal and vertical counting circles;
- treasure tray, on which there are three adjusting screws, as well as a round level;
- telescope;
- guide and fixing screws;
- plumb line;
- counting microscope.
Bringing the theodolite to the working position - setting up the
device Before starting the measurements, the is placed in the working position of the theodolite. The maximum accuracy of the calculation depends on how reliably fixed the device is. Bringing the theodolite in the working position is to install it above the point: centering, leveling, and installing a pipe for observation.
Centering of the theodolite serves to align the limb of the horizontal circle with the plumb line that passes through the point of the device. The horizontization of the theodolite leads the axis of rotation to a sheer state. The plane of the limb occupies a horizontal position at this time.
Primary horizoning is done during the installation of the tripod, and precise adjustment is done with screws using a cylindrical level. However, the theodolite must still be able to use. To get the necessary knowledge for this, naturally, it would be nice to pass at least an initial training course, since handling such a high-precision device does not tolerate negligence.
This article does not serve as a tool for acquiring the skills of working with the theodolite, but only gives general information on how to handle this device.
Measurement of vertical angles with a theodolite - how to do it yourself?
First, the device must be secured securely on the tripod. Then choose two points of the object, the measurements taken. The visual tube is guided by means of a screw and a dioptric ring to selected points.
After that, the vertical filament of the telescope is combined with one of the points and the data is read from the horizontal circle. Gradually loosening the fixation screw, the pipe is moved clockwise to another point and readings are also taken.
The angular measurement of the theodolite is sometimes done using circular reception, which is useful when one has to measure from one point. To do this, the theodolite is installed in the right place. The limb should be as close as possible to zero.
Then begin to rotate the alidade until the zero-point bar of the microscope with the zero stroke on the limb is completely aligned. Next, loosen the clamp slightly and point the pipe to the point. At the end of the measurements, tighten the locking screw and make calculations.
The theodolite measures horizontal angles regardless of its position. To conduct such measurements, the telescope is alternately pointed at a pair of points, between which it is necessary to measure and simultaneously count down the horizontal circle. The value of the angle is determined based on the sampling difference. If you still have questions about how to use the theodolite, the video on the page of the site will help you learn more about all the subtleties of this work.
