| record number: | 67 |
| instrument type: | self reducing tacheometer |
| manufacturer: | Carl Zeiss Jena |
| serial number: | 416149 |
| model: | Dahlta 010A |
| weight: | 4.48 kg |
| dimensions (l/w/h): | 23/21/30 cm |
| year of manufacture: | 1979 |
| centering and leveling the instrument: |
optical plummet
circular level toric level on the alidade compensator |
The self-reducing tacheometer was made in 1979 and represents the pinnacle of autoreducer technology. The color and shape are typical of Zeiss instruments of the last era of optical instruments. The precision of the tacheometer, and above all its functionality, allowed it to be used effectively for polar detail measurements. The distinctive feature of autoreducers is the shape of the crosshairs. In addition to the vertical hair, it has a base and a distance hair and several elevation hairs - curves with different constants. By reading the division on the tacheometric staff, the instrument allows direct determination of the horizontal distance and the height difference to the measured point.
The instrument was used for teaching and professional work at the Faculty. It was used to produce a number of topographic plans for the extensive area of the former Žirovski vrh uranium mine. The instrument was used for professional work until the end of the 1980s and for teaching work even later.
The tacheometer is in the same condition as when it was originally taken out of service.
| horizontal circle | vertical circle | |
|---|---|---|
| diameter: | protected, 86 mm | protected, 86 mm |
| type of division: | engraved division | engraved division |
| limb implementation: | glass bracket | glass bracket |
| division: | sexagesimal/sexadecimal | sexagesimal/sexadecimal |
| unit: | 1° | 1° |
| Reading | ||
| number of reading points: | 1 | 1 |
| reading device: | scale microscope | scale microscope |
| number of units: | 60 | 60 |
| graduation unit: | 1', estimation 6'' | 1', estimation 6'' |
| repetition: | Mahler membrane | by the vertical circle it also has an additional division for the tangent of the angle |
| Distance measurement | ||
| principle: | optical, parallactic triangle with a variable angle and a base on a vertical staff | |
| precision: | 10 – 20 cm per 100 m for distances, 5 to 10 cm per 100 m for height differences | |
| range: | up to 300 m, depending on the tacheometric staff length | |
| Telescope | ||
| diameter of objective: | 40 mm | |
| magnification: | 25 x | |
| type: | telescope with internal focusing | |
| cross hairs/reticule: | basic hair, vertical hair, distance and elevation hairs in the face I | |