Any construction or survey workrequire accurate calculations of the differences of the landscape in a particular area. Conventional surveying instruments, such as leveling, tape measure, range finder and theodolite, can handle small areas, but when it comes to thousands of square meters, measurements can take weeks. Most often, customers prefer contractors performing work as soon as possible, so in the field of modern geodesy, work without an electronic total station becomes more and more complex.
What it is?
Тахеометр - это современный геодезический прибор.In his power to produce fast and accurate shooting with a complete picture of the relief. It combines traditional geodesic devices: a theodolite, a range finder and an electronic data logger, all this despite its compact size. A total station is a device that can perform calculations at a distance of up to five kilometers with an accuracy of one centimeter and transmit data via Wi-Fi or Bluetooth.
History
Almost half a century ago, the first instruments were created,distantly resembling total stations. At first, the theodolite and the light range meter were installed independently of each other, then they were combined into one case, and later equipped with a special panel through which the angles could be entered. The Swiss engineers created the first full-time total station by replacing the angle reading from optical to electronic. With this modernization, the possibility of substantial automation of geodetic works. Electronic tachometers became widely known on the market for geodetic instruments about twenty-five years ago.
Principle of operation
The instrument is a fairly advanced instrument.however, it has recently been fundamentally modernized. Older models in their work are based on the phase method. It consists in calculating the phase difference between two rays: the projected and the returned.
More modern models are based on the impulse method. It consists in counting the time it takes the laser beam to travel from the total station to the reflector and return.
The range of the device in non-reflectivemode depends on how the painted surface on which the projection of the beam. The distance when choosing a dark and matte surface is reduced several times in comparison with a light and smooth one, but it will not exceed 1200 meters anyway. Measurements at large distances are made only in the reflection mode, in which the distance is at least five kilometers.
Manufacturers
Various electronic tachometers are widely represented on the Russian market. These are Japanese, Swiss, Swedish and American brands. Behind each of them is a long history of development.
The Japanese company Sokkia Topcon for over a hundred years has been presenting its products in the geodesy and construction market. Devices of this brand are of consistent quality and high accuracy.
Leica Swiss tacheometers appeared on the market in1990, after a merger of several companies and a reorientation towards geodetic equipment exclusively. Leica Geosystems products enjoy good demand in the geodesy market, not only terrestrial, but also satellite.
The Swedish company GeoMax is famousmanufacturer of surveying instruments. It was also formed in the nineties of the last century and to this day it successfully competes with Leica on the European market for geodetic equipment. The line of GeoMax models, including hardware and software, is highly valued by engineers for their high quality and measurement accuracy.
Nikon tacheometers manufactured by TrimbleNavigation. This manufacturer began its history in 1978. At first, only navigation devices for the needs of maritime navigation descended from the conveyor of a young American company, and later, about twenty-five years ago, with the development of space positioning, Trimble engineers began to work on GPS navigators. Surveying equipment, including tacheometers, have expanded the company's product range since 2003, after the purchase of the Nikon brand.
Brand Comparison
Although many say that within the same classthere are some differences between the models of tachometers from different manufacturers; this is not entirely true. In the Russian market the most well-known tachometers are Sokkia, Leica and Nikon. If we conditionally divide them into classes, then the Swiss brand Leica will receive the first, Sokkia - the second, and Nikon and the rest of the brand - the third. The same "hierarchy" and have the prices of total stations of these brands.
Leica - high quality Swiss appliances,they are good for everyone except the price. These tacheometers have their own characteristics, which may initially seem inconvenient to someone, for example, a serif mode and the removal of points in nature. The price for devices of this brand starts at half a million for a simple model for building needs. Leica engineering tacheometers cost between five and seven million.
Sokkia Reviews
Sokkia devices, conditionally occupying second placeafter Leica, they are distinguished by reliability, convenience and traditional Japanese quality. Their plus is also in a clear interface. Sokkia tacheometers are equipped with good range finders, they perfectly withstand various operating conditions. There are also disadvantages, for example, the rather old model Sokkia 530R has problems with measuring through small obstacles (for example, if reinforcement is in the way). The price tag is noticeably lower than that of the Swiss colleagues, for example, the Sokkia iX-503 robotic engineering total station will cost just over a million rubles.
Most often, the buyers are stopped not so much by the price as by the fear of the complexity of the automated models, because to work with them it may not be enough to simply read the instructions of the total station.
Nikon shoppers
Although we have given the third tacheometers of this brandplace, it does not mean that the devices do not meet the standards and are unsuitable for work. First, they are the most budget in the market. Lightweight, convenient and compact total station of this brand can be bought for seven hundred thousand rubles. The cheapest model will cost several times cheaper, which makes Nikon one of the most affordable total stations on the Russian market.
These tacheometers are assembled in China, but the ownersclaim that it does not affect their performance. They are quite easy to tolerate harsh operating conditions (dust, dirt, rain) and cope with their tasks. For example, the aforementioned Sokkia 530R has problems with measuring through small obstacles, and the Nikon models do not have it; moreover, the owners say that it copes even if it is difficult to see a milestone.
Before the purchase
If the budget for the total station is already defined andit remains only to choose a model, it is worth remembering that the basic characteristics of devices of one price segment are quite similar. The difference most often lies in the fine details, the interface and the software, so you need to make a clear plan of the tasks that the total station must perform in a particular organization. For example, if it is intended to work in particularly harsh conditions, such as low temperatures or constant humidity, attention should be paid to special models that most manufacturers have. Experienced suppliers will be able to point out some or other disadvantages of a particular model.
