SUBTENSE BAR EBOOK DOWNLOAD!
Get this from a library! Subtense bar traverse. [Gilbert R Fish; U.S. Coast and Geodetic Survey.]. Tacheometry is a system of rapid surveying, by which the horizontal and vertical positions of Another device used in tacheometry is the subtense bar. This is a. CI. —"Beams and Slabs Spanning in. One Direction". The gist of this clause is that beams yvhich are continuous should be designed as continuous beams.
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File:Subtense - Wikimedia Commons
Thus all the measurements requisite to locate a point both vertically and horizontally with reference to the point where the tacheometer is centred are determined by an observer at the subtense bar without any assistance beyond that of a man to hold the staff.
The ordinary methods of surveying with a theodolitechain, and levelling instrument are fairly satisfactory when the ground is relatively clear of obstructions and not very precipitous, but it becomes extremely cumbersome when the ground is covered with bushor broken up by ravines.
Chain measurements then become slow and liable to considerable error; the levelling, too, is carried on at great disadvantage in point of speed, though without serious loss of accuracy.
These difficulties led to the introduction of tacheometry.
For the photo above, I obviously managed to assemble the gear. I lost count of the times I got the subtense bar crossed, but eventually it went together. How does one do this under fire?
The above images show the bar folded, its short telescope; and the subtense bar bar end in the centre, and the flat bar end on the right. Below the central nount is a lockable fine adjustment so that the bar can be made precisely at right angles to the measuring theodolite.
Wild Heerbrugg Subtense Bar Staff Basislatte 2 M | eBay
subtense bar In daylight, back illumination is provided by the upwards facing window and white painted surfaces.
The brightness is adjustable.
- Construction Measurements - B. Austin Barry, Benjamin Austin Barry - Google Livros
- Untitled Document
- Measuring distance using subtense method.
- Wild Heerbrugg Subtense Bar Staff Basislatte 2 M 58265
- File usage on Commons
The image on the right shows the bracket connected to the window target clamped between two nuts. Loosening these allows the precise length between the bar's targets to be adjusted.
10-FOOT PORTABLE SUBTENSE BAR
Two Starrett micrometer adjusting wrenches are supplied, but how a squaddy could sensibly adjust this critical distance in the field is beyond me.
The latter has a 'collimator' that can be viewed from the theodolite to check that the subtense bar is a a right angle to the line of sight from subtense bar theodolite to the centre of subtense bar bar.
The two targets can be illuminated through a power socket in the centre. The subtense bar is subtense bar for transport and comes with a carrying bag.