A Topographic Abney Level is an instrument used in surveying which consists of a fixed sighting tube, a movable spirit level that is connected to a pointing arm, and a protractor scale. The Topographic Abney Level is an easy to use, relatively inexpensive, and, when used correctly, an accurate surveying tool. The Topographic Abney Level is used to measure degrees, percent of grade, topographic elevation, and chainage correction. By using trigonometry the user of a Topographic Abney Level can determine height, volume, and grade. The Topographic Abney Level is used at the eye height of the surveyor and is best employed when teamed with a second surveyor of the same eye height. This allows for easy sighting of the level and greater accuracy. A ranging pole can be marked at the eye height of the level user or the approximate location of the eye height (i.e. chin, nose, top of head) of the level surveyor must be know of the ranging surveyor.
Famous quotes containing the word level:
“On a level plain, simple mounds look like hills; and the insipid flatness of our present bourgeoisie is to be measured by the altitude of its “great intellects.””
—Karl Marx (1818–1883)