| record number: | 65 |
| instrument type: | theodolite |
| manufacturer: | Carl Zeiss Jena |
| serial number: | 242753 |
| model: | Theo 120 |
| weight: | 2.53 kg |
| dimensions (l/w/h): | 13/14/25 cm |
| year of manufacture: | 1971 |
| centering and leveling the instrument: |
plumb bob
toric level on the site of the alidade compensator |
The theodolite was made in 1971. Although small, its functionality is comparable to the larger, seemingly much more complex Zeiss theodolites of the time. The positioning of the levels, compensator, the line microscope, repetition device and Reichenbach crosshairs simplify the measurement process. Measurement precision is lower compared to more complex instruments. The measurement resolution by determining a fraction of the division graduation unit is 1'.
The instrument was used for teaching purposes for simple polar measurement and staking out. It is in the same condition as when it was originally taken out of service. Minor paint damage has been lacquered.
Characteristics
| horizontal circle | vertical circle | |
|---|---|---|
| diameter: | protected, 61 mm | protected, 61 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: | line microscope | line microscope |
| number of units: | / | / |
| graduation unit: | 10', estimation 1' | 10', estimation 1' |
| repetition: | Mahler membrane | / |
| Telescope | ||
| diameter of objective: | 32 mm | |
| magnification: | 16 x | |
| type: | telescope with internal focusing | |
| cross hairs/reticule: | Reichenbach's crosshairs, constant 100 | |