How to Use:
It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide angular readouts. These indicate the orientation of the telescope, and are used to relate the first point sighted through the telescope to subsequent sightings of other points from the same theodolite position. These angles can be measured with great accuracy, typically to millenarian or seconds of arc. From these readings a plan can be drawn, or objects can be positioned in accordance with an existing plan. The modern theodolite has evolved into what is known as a total station where angles and distances are measured electronically, and are read directly to computer memory. When the telescope is pointed at a target object, the angle of each of these axes can be measured with great precision.
Main article: Temporary adjustments of theodolites
Temporary adjustments are a set of operations necessary in order to make a theodolite ready for taking observations at a station. These include its setting up, centering, leveling up and elimination of parallax, and are achieved in four steps:
Setting up - fixing the theodolite onto a tripod along with approximate leveling and centering over the station mark.
Centering - bringing the vertical axis of theodolite immediately over station mark using a centering plate.
Leveling - leveling of the base of the instrument to make the vertical axis vertical usually with an in-built bubble-level.
Focusing - removing parallax error by proper focusing of objective and eye-piece. The eye-piece only requires adjustment once at a station. The objective will be re-focused for each subsequent sightings from this station because of the different distances to the target.
·Large LCD display.
·Good visibility of the laser line.
·Independent tilt sensor can auto corrected.
·Combined with various models of EDM's to form total station system.
·More convenience when the instruments is combined with the Diagonal Eyepiece.
·Connected with electronic book makes data to be auto-recorded and auto-processed maps.
·International common function modes are adopted to make operation simple and standard.