Two options of using eyepiece scales for mineorientation

Abstract

Eyepiece scales are known in surveying practice under the name of Bratgun scales, by whom they were proposed for observing the fluctuations of the plumb line instead of the usual scales installed near the plumb lines. Bratgun's proposal was used for orientation through two shafts, and for this purpose mining theodolites are equipped with an additional eyepiece elbow with an eyepiece scale and reticle. To use the eyepiece scale, the eyepiece tube of the theodolite telescope is replaced with a tube containing an eyepiece scale. The scale is applied mechanically or photographically to the glass. The value of one scale division depends on the focal length of the sighting tube; in mining theodolites it is made equal to about 50″. The high accuracy of the scale markings and the small value of the scale divisions make it possible to use eyepiece scales not only when orienting through two shafts, but also through one. This article proposes a method for using eyepiece scales to solve one of the most important tasks in surveying: the orientation of mine surveys. This method introduces technical improvements in the production of orientation and reduces the time for its execution. The proposed methods of using eyepiece scales increase the speed of orientation, do not require capital and bulky platforms for scales, and allow the observer to make measurements and observations in the mine in better conditions.

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