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   OPTICAL SCALE-READING THEODOLITE  
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Maker

Kern, Aarau (Switzerland)

Model

K1-S

Serial Number

256721

Dimensions

Telescope Length 160mm, Height 215mm

Image

Kern K1-S Theodolite

Description

This is an optical scale-reading theodolite with a scale microscope as the reading device and is designed for traversing, small triangulation networks, set-out surveys and stadia measurements. This instrument also incorporates an automatic vertical circle index which in turn eliminates the need for an altitude bubble and makes vertical circle reading easier. The scale microscope beside the telescope is a simple, but accurate circle reading device. The readings on the horizontal and vertical circles are visible in the microscope together with the corresponding microscope graduation projected onto them. The graduated circle can be easily read with an accuracy of 30" on the simple and clear microscope scale, which consists of lines with thickness corresponding to that of the circle graduation lines. These lines are about 0.01 mm thick and are easily visible in the microscope which has a magnification of about 25x. A special feature of this instrument is that the horizontal circle is numbered in both directions (clockwise and counter-clockwise). Thus the calculation of supplemental angles, necessary for some setting out of works is not required.

The magnification of the telescope is 30x, the diameter of the objective lens of the telescope is 45 mm, and the shortest pointing distance is approximately 1.7 m. The graduated circle diameter of the horizontal circle is 89 mm and the vertical circle diameter is 70 mm. The bubble sensitivity of the plate level is 30" per 2 mm run.

In the instrument, a pendulum compensator, consisting of a lens suspended under gravity, with an oscillation damping arrangement, is incorporated in the light path. The accuracy of this compensator is 6 s". 

History & comments

The instrument has a connection for the power supply of an external telescope mounted EDM (Electronic Distance Measurement) device.

Conservation

In a rectangular metal case

Condition

Good

Remarks

  • Weight of instrument is 4.6 kg
  • Catalogued by T. Ko
  • Updated by F. Pall

Dates

Manufactured in 1965 (approx). Catalogued in 1997.

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