Universal instrument
Universal instrument (also universal ) is the name for angle measuring devices in astronomy with which precise angle measurements can be carried out in both directions ( azimuth and elevation angle ).
This is where they differ from horizontally fixed (non-swiveling) instruments such as the meridian circle , the passage instrument and other transit instruments of astrometry , with which v. a. Time determinations and star locations are measured.
The universal instruments are equipped with particularly precise tubular vials that have pars values of just a few angular seconds . The fine movement of the two axes of rotation must enable target accuracies below 1 "and the pitch circle readings to at least 0.5".
Well-known types of universal instruments are the Wild T4 from Wild Heerbrugg and the DKM3-A from the former company Kern & Co AG (both in Switzerland). Previous models were made around the turn of the century a. a. produced by Starke & Kammerer (Vienna). Most of the instruments have a broken telescope , which makes them more compact and easier to use.
The theodolites used in geodesy are related to the astronomical universals. However, they have a smaller and more compact design so that they are more manageable and can cope with the often harsh operating conditions. The modern digital total stations in engineering geodesy also belong to the same group of instruments, but are equipped with additional devices for electronic distance measurement .
See also
- Astrometry , astrogeodesy
- Fundamental astronomy
- Direction measurement , azimuth measurement
- Location determination
literature
- Karl Ramsayer: Geodetic Astronomy , Metzler, Stuttgart 1970
- Albert Schödlbauer: Geodetic Astronomy: Basics and Concepts. deGruyter Berlin-New York 2000, ISBN 3-11-015148-0 .