Key surveying and engineering product vendors answer questions from users.
Most total stations allow the user to turn the tilt compensator on or off. If the compensator is off, the vertical angle will be incorrect in the magnitude in which the instrument is out of level in the observed direction. A typical total station’s level vial specification is 30"/2mm. A vertical angle error of 30" (one level vial graduation) would cause an elevation error of 0.073 ft in a 500 ft distance with the compensator off.