Angle Gage, Mine

Angle Gage, Mine 

an instrument for measuring horizontal and vertical angles and distances in mine surveying where high precision is not required—for example, in surveying the stopes in mine shafts or in setting the direction of substory mine excavations. A mine angle gage differs from a theodolite in its simpler design and the lower accuracy of readings on the graduated circles. Tachymeters with visual or projection-visual range finders are a common type of mine angle gage.

A mine angle gage has a horizontal Circle and a vertical semicircle with open graduated circles; it also has a sighting tube that is mounted eccentrically relative to its horizontal axis of rotation and is equipped with a range finder, a circular level, and clamping devices. The range finder measures distances up to 45 m with a relative error of measurement m_e = 1:100; the limits of measurement of vertical angles m_v = 15°.

REFERENCES

Ogloblin, D. N., and I. Ia. Reizenkind. Novye marksheiderskie pribory, 2nd ed. Moscow, 1967.
Spravochnikpo marksheiderskomu delu, 3rd ed. Moscow, 1973.