| record number: | 38 |
| instrument type: | theodolite |
| manufacturer: | MOM |
| serial number: | 554588 |
| model: | 17B |
| weight: | 4.98 kg |
| dimensions (l/w/h): | 18/16/27 cm |
| year of manufacture: | 1945 |
| centering and leveling the instrument: |
plumb bob
circular level two perpendicular toric levels on the alidade precise reversible levelling toric level on the telescope vertical circle level |
The theodolite was made in the 1950s. Although well-known manufacturers were producing much more complex optical theodolites at this time, MOM still insisted on this model, which has the method of levelling, centring and reading on circles typical of instruments from the second half of the 19th century. The ordinary plummet, the rectangular alidade toric level, the vertical circle level, the levelling toric level and the verniers were all becoming history at the time.
The small but complex classic theodolite makes it possible to read the horizontal division by observing the vernier with a microscope, and the vernier of the division of the vertical circle is observed with a lens. The graduation unit of the division is 15'' or 20'', thus being a minute-order theodolite.
In 2016, the instrument was cleaned and the vertical circle was re-polished.
| horizontal circle | vertical circle | |
|---|---|---|
| diameter: | protected, 120 mm | protected, 90 mm |
| type of division: | engraved division | engraved division |
| limb implementation: | silvered metal bracket | silvered metal bracket |
| division: | sexagesimal/sexadecimal | sexagesimal/sexadecimal |
| unit: | 10' | 20' |
| Reading | ||
| number of reading points: | 2 | 2 |
| reading device: | scale microscope | vernier |
| number of units: | 30 | 60 |
| graduation unit: | 15'' | 20'' |
| repetition: | clamping and micrometer screw | / |
| Telescope | ||
| diameter of objective: | 30 mm | |
| magnification: | 28 x | |
| type: | telescope with internal focusing | |
| cross hairs/reticule: | Reichenbach's crosshairs, constants 100 and 200 | |