Line microscope
A line microscope is a reading device on theodolites .
In the case of simple theodolites, the indication of the direction is usually read off via an index line. Depending on the size of the pitch circle, this offers a reading accuracy in the dgon range. An estimate can be made on cgon.
By using a line microscope, reading to cgon accuracy is possible. The reading was quick, but it is in the low accuracy range.
In most cases, reading takes place on the tube (lens-bearing tube), which is attached next to the telescope . The reading of the horizontal or vertical circle is reflected in the tube via a lens system .