What is face left and face right in surveying?

The terms “Face Left” and “Face Right” originally refered to which side of the telescope the vertical circle of a theodolite lay when the telescope was reversed by rotating it 180° about its tilting axis. The saying goes back to the origins of Theodolites. It has nothing to do really with the direction you are reading.

Why do we measure face left and face right?

Reading an angle face right and face left will eliminate the errors due to the non adjustment of the line of collimation and the trunnion axis. We won’t do any adjustment and assume the instrument is calibrated. Both axes of a theodolite are equipped with graduated circles that can be read out through microscopes.

What is face right observation?

(ii) Face Right: When the Vertical Circle of a Theod is situated on the right of the observer and the observation or reading taken with this face is called Face Right Observation or Reading.

What is FL and FR in surveying?

After correctly setting up the theodolite and sighting a target point, we take readings on the horizontal and the vertical circle in both face left (FL) and face right (FR) positions.

What does face left mean in surveying?

Face right is when the vertical circle of an instrument is in the right side of the observer and face left is when vertical circle of an instrument is in left side of the observer while taking the readings during survey.

What is meant by face left observation?

(i) Face Left: When the Vertical Circle of a Theod is situated on the left of the observer and the observation or reading taken with this face is called Face Left Observation or Reading.

What is traversing in survey?

Traverse is a method in the field of surveying to establish control networks. Traverse networks involve placing survey stations along a line or path of travel, and then using the previously surveyed points as a base for observing the next point.

What is latitude and departure in survey?

LATITUDES AND DEPARTURES: Background The latitude is the y component of the line (also known as northing), and the departure is the x component of the line (also known as easting).

What does face left mean?

Definition of left face : the act of turning 90 degrees to the left from the halted position of attention as a military maneuver —often used as a command — compare about-face, right face.

When vertical circle is left side of observer that position is called as face left?

Face left observation: While taking the reading, if the vertical side is towards the left of the observer then it is called face left observation. (Also called as Telescope Normal condition).

How do you do traversing?

Chain traversing is done by taking linear measurements only. Hence, chain or tape is enough for chain traversing. The angle between the adjacent traverse lines is measured using the chain angles concept. Chain traversing is performed in areas such as ponds etc.

How do you measure included angles in traversing?

Traversing by Included Angle An included angle at a station is either of the two angles formed nby two survey lines meeting there and these angles should be measured clockwise. The method consists simply in measuring each angle directly from a back sight on the preceding station. The angled may also be measured by repetition.

How do you check for angular work in geometry?

The following are checks for the angular work: Travers by included angles: The sum of measured interior angles should be equal to (2N-4), where N=number of sides of the traverse. If the exterior angles are measured, their sum should be equal to (2N=4)p/2

How do you measure the direction of the lines?

The direction of the lines can be measured by the techniques discussed in Compass surveying and Theodolite. The precision usually specified for traversing requires the use of steel tape and the theodolite.

What is a deflection angle in civil engineering?

A deflection angle is an angle in which a survey line makes with the prolongation of the preceding line. It is designated as right (R) or left (L) as it is measured clockwise or anti-clockwise from the prolongation of the previous line.