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(or tacheometer), a geodetic instrument used in tachymetric surveying to measure the position of a point relative to the instrument station. The tachymeter permits determination of the horizontal angle β, the vertical angle v, the distance s, and the difference h between the elevation of the point and the elevation of the instrument station.

Several types of tachymeters exist. The rotary tachymeter is a repeating transit that has a vertical circle with a cylindrical level; the telescope is provided with stadia hairs. Nomographic and autoreducing tachymeters permit h to be determined from a vertical rod and a nomograph visible in the field of view of the telescope; such tachymeters make use of a double-image range finder to determine horizontal s from a horizontal rod. In another type of tachymeter, the base line is an integral part of the instrument. Such a tachymeter can be used to determine horizontal s directly and to find h from the measured angle v.

tachymeter, tacheometer, tachometer

A surveying instrument designed for use in the rapid determination of distance, direction, and difference of elevation from a single observation, using a short base which may be an integral part of the instrument.
References in periodicals archive ?
This stand is composed of the following elements: a static frequency converter that supplies a three-phase asynchronous motor, a digital tachymeter for rpm measurement, a central unit and monitor for control and monitoring, and a single-phase synchronous generator for loading the three-phase asynchronous motor (Livinti, 2007).
The experimental works involved taking pictures of plate targets for the set values of the zenith angle and horizontal direction of the tachymeter telescope and shifts of the micrometric table in the horizontal plane.
For measurements are used two electronic tachymeters.
It can also be used to measure the actual speed on the tachymeter scale over a reference distance of 1,000 metres, forexample.
Disc 1 is driven by electromotor 5 where the rotation velocity is calibrated by the transistor converter 6 for the frequency regulation "Mitsubishi" (type A500); number of rotations is measured by nonconcact digital tachymeter "Sanwa" (type SE-100).
The landslide monitoring systems consist usually on in-situ borehole measurements (inclinometers and piezometers) and on the surface, it consist of a set of geodetic benchmarks measured with GPS and tachymeter.
Made of brushed titanium, the case is surmounted by the bezel, also with brushed finish but with edges in polished titanium, which carries the engraved numbers of the tachymeter scale.
At first glance, this watch is distinguished by its expert blend of colors and materials: black, steel and a dynamic dash of orange picked up on the sweep seconds hand, the tachymeter numerals and the stitching sailcloth strap.
Then on October 3, 2002, the total station angle and distance measurements with Leica TCA 2003 tachymeter in a 10 measurement series were realized.
Tenders are invited for Q / U2CD / HA181 / GA283 - 30 TDC measuring equipment; 12 SE Tachymeter Reflector (6001300803-BAAINBw U2.
Tenders are invited for Replacement procurement of a tachymeter for the field of surveying / mapping / real estate of the ws duisburg-rhine and cologne in 2017