Total stations functionality

Modern Total station, as well as its optical predecessor, measures corners and distances up to a mark or a support with a reflector. These primary measurements form a basis for the subsequent, sometimes the difficult calculations made by the built in or external controller. Accuracy of measurement blocks or modules of measurement of corners distances and determine the module of the equaliser.

If to speak about accuracy angular measurements, as a rule, are limited by accuracy 1 ”, and linear 1mm + 1ppm. This threshold, first of all is connected not with technical problems of measuring systems, and with influence of an environment. Higher accuracy declared in tacheometer’ characteristics of separate manufacturers, practically is not achievable at usual works and conditions because of influence of an environment and errors of a centering and prompting. Accuracy of measurement of the elementary tacheometer as a rule is not worse 56 ” for angular measurements and 3mm + 3rrm for linear. For observance of accuracy of angular measurements the range of indemnification of influence of corners of an inclination of vertical and horizontal axes is extremely important. Now Total Station Geodimeter has the greatest range of work (± 6 '). This size is especially essential at work tacheometer from a support.

The range finder tacheometer is characterized not only accuracy, but also range. As a rule, it is range of measurement of distances up to one prism. It is necessary to note, that these characteristics are connected with each other. Notwithstanding what the significant part of volume of measurements tacheometer does not exceed 5001000 m, periodically it is necessary to measure much longer distances. Therefore the best today are range finders with accuracy of measurements not below 2mm + 2rrm at range 30004000 m. These parameters should become standard in the future for the majority of tacheometer. The increase in range of measurements to the detriment of accuracy is inexpedient and it is inefficient.

It is necessary to note, that a number of manufacturers obviously overestimate a parameter of range, stipulating special conditions of a transparency of atmosphere at which the certain range of measurements is achievable. For example, it is resulted such parameter of a transparency of atmosphere, as absolute visibility for 40 km. It is necessary to mean, that for the user definition of atmosphere conditions is practically impossible. Besides it working in city conditions along motorways the transparency of an atmosphere significantly decreases because of a gassed condition of an atmosphere.

Recently wide circulation has received Total station with a range finder, allowing to measure distances directly up objecting without a reflector. As a rule, range of such measurements does not exceed 100150m, and accuracy lies within the limits of 1020mm. It is necessary to note dependence of accuracy of measurements on properties of a reflecting surface and absence of reliable fixing of a point of measurement. It is lacks of the given systems.