This article is to help explain the differences in
Transits, Theodolites, Total Stations, and Levels.
Transits
A transit is type of theodolite that features a
telescope that can "flip over" which would allow
easy back-sighting and doubling of angles for error
reduction. Some transit instruments were capable of
reading angles directly to thirty arc-seconds. In
the last 50 years, transits have been known as a
simple form of theodolite with less precision,
lacking features such as scale magnification and
mechanical meters. The importance of transits has
been decreasing since more compact, accurate
electronic theodolites have become widespread tools,
but transits still find use as a lightweight tool
for construction sites. Please note that some
transits do not measure vertical angles.
Theodolites
A Theodolite is a instrument for measuring both
horizontal and vertical angles, as used in
triangulation networks. It is a tool used in the
surveying and engineering industry, but theodolites have
been adapted for other specialized purposes as well.
A theodolite consists of a telescope mounted movably
within two perpendicular axes, the horizontal or
trunnion axis, and the vertical axis. When the
telescope is pointed at a desired object, the angle
of each of these axes can be measured with great
precision, typically on the scale of arcseconds. The
measurements are typically recorded by hand as they
are not recorded by a computer or data collector.
Total Stations
A total station is an optical instrument used in
modern surveying. It is a combination of an
electronic theodolite (transit), an electronic
distance measuring device (EDM) and software running
on an external computer, such as a laptop or data
collector.Levels
The builder's level is often mistaken for a transit,
but is actually a type of inclinometer. It measures
neither horizontal nor vertical angles. It simply
combines a bubble level and telescope which allows the
user to visually establish a level line of sight along a
plane.
Copyright 2006 EngineerSupply