Carl Zeiss Jena Theo 010
theodolite Carl Zeiss Jena Theo 010
record number: 35
instrument type: theodolite
manufacturer: Carl Zeiss Jena
serial number: 159830
model: Theo 010
weight: 5.55 kg
dimensions (l/w/h): 14/18/29 cm
year of manufacture: 1953
centering and leveling the instrument: optical plummet
circular level
toric level on the alidade, centrally set
vertical circle level

The second-order theodolite was made in 1953. The instrument has a modern design and is the predecessor, at least for students, of the legendary Theo 010A. The two models differ mainly in the way the vertical circle index is adjusted. The Theo 010A has a coincidence vertical circle level, which requires a longer procedure when measuring zenith distances.

The instrument has a modern way of determining readings on circles. It was retained until the last models of the Carl Zeiss Jena optical theodolites were manufactured in the 1980s. With the coincidence of the diametral points of the circle division by means of a wedge optical micrometer, it provides the resolution of 1''. The divisions are read through a single microscope, and a special screw is used to switch between the two circles.

The instrument was used extensively for teaching purposes, especially for measuring angles in horizontal and vertical trigonometric nets. It is still in the same excellent condition as when it was originally taken out of service.

Characteristics
horizontal circle vertical circle
diameter: protected, 84 mm protected, 60 mm
type of division: engraved division engraved division
limb implementation: glass bracket glass bracket
division: sexagesimal/sexadecimal sexagesimal/sexadecimal
unit: 10' 10'
Reading
number of reading points: 1 1
reading device: wedge optical micrometer wedge optical micrometer
number of units: 600 600
graduation unit: 1'' 1''
repetition: clamping screw /
Telescope
diameter of objective: 53 mm
magnification: 31 x
type: telescope with internal focusing
cross hairs/reticule: Reichenbach's crosshairs, constant 100