CM 2105
Builder’s level - Can be used to turn angles, and the scope can be tilted for sighting
A versatile instrument
One of the most inexpensive instruments
Dumpy level - the instrument of choice
Hand level - also called a sight level
Can be used to roughly determine elevations for cut or fill stakes
Automatic levels - create a horizontal line of sight
Height of instrument - the elevation of the line of sight of the instrument. Determined by adding the backsight to the known elevation
Vertical angles - horizon is parallel to the earth surface and zenith is perpendicular to the horizon
Horizontal angles - Measured in horizontal planes.
The angle is measured between two points that are sighted from the instrument
Deflection angles - horizontal angles that are measured from a prolongation of a preceding line
Interior angles - horizontal angles that are often measured to determine the angles of a closed geometric figure
Exterior angles - measured outside closed polygon
Sum of interior and exterior angle is 360d
A total station measures with a 360 degree prism
How many prisms are apart of an optical angle reading system
2-4 prisms
What do you include in an field book ← what should go in it
Title page
Table of contents
Legend of symbols
North arrow
Identification number
Date, time, and weather
Sketches
English level rod - feet, tenths, hundredths
Metric level rod- meters, centimeters, millimeters
What does it mean to close the loop and how do you close it
Means to end the level loop at the benchmark where you began or at another benchmark
Angle measurement - determines the exact angle between two lines or points using surveying instruments
Angle layout - involves marking or establishing a specific angle on-site based on design plans
Backsight - a reading on a rod held on a point whose elevation is known
Foresight - a reading on a rod held on a point whose elevation is UNKNOWN
Turning point - a point used in the differential leveling process to temporarily transfer the elevation from the HI
Elevation - the vertical distance above a zero datum
Known point - a predetermined reference point with accurately measured coordinates, elevation, or both
Cold weather - steel contracts (shrinks)
Hot weather - steel expands (stretches)
Flat ground - ideal condition for chain or tape; minimal impact
Bumpy or uneven ground - tape may sag or bend; overestimates the actual distance
Sloped ground - tape follows terrain, not the horizontal distance; measured distance is longer than actual
Steel tape - a flexible measuring tool made of thin hardened steel or stainless steel, used for precise linear measurements
Steel chain - made of thick steel links connected by small rings, used for rough measurements in field surveying
What is the sum of the following four angles turned from an occupied point?
33d 22’ 22”
22d 33’ 33”
44d 55’ 55”
55d 44’ 44”
Answer - 156d 36’ 34”
The level rod in the differential leveling process has 100ths marked on a decimal rod. The top part of the mark is?
Answer - Even
When marking a line or grade on a job site which of the following best describes the placement of these markings?
Answer - Plumb, level, straight
What is the calculated discrepancy ratio from the following information?
The distance for Line A-B was measured, with the two measurements being 100.05 ft A-B and 99.95 ft B-A.
Answer - 1/1000
Deflection angle is a field angle best described by which of the following statements?
Answer - Angle measured off a prolongation of a baseline
Record keeping is an important part of surveying. Which of the following is a legal document on a construction site?
Answer - Engineers field book
Nodal point 2 has an incoming line from 1 and an outgoing line to 3. Calculate the two angles defined by the following: Line 1-2 has a direction of 95 degrees, and Line 2-3 has a direction of 158 degrees?
Answer - 243d & 117
Convert the bearing S22d 21' 19" E to an azimuth.
Answer - 157d 38’ 41”
Which of the following is qualified for the location of property lines?
Answer - Registered Land Surveyor
Which of the following are angle-measuring instruments?
Answer - total stations, transits, theodolites
When you want to locate a point on the job site and an angle needs to be turned to locate it, you are performing angle _____
Answer - layout
Which of the following is a field angle used when working with a total station?
Answer - Direct angle
Reverse is when the vertical circle is on the left as you are sighting through the telescope, and direct is when the vertical circle is on your right as you sight through the telescope
Answer - false
In the process of turning angles, procedures such as direct, reverse, closing the horizon, transverse angles, and layout are performed
Answer - true
Which part of a total station lines up directly with the vertical axis?
Answer - optical plummet
If an angle is turned off of this extended, it is called a(n) _____ angle.
Answer - deflection
Measurement angles are critical to jobsite field observations. When performing a series of measurements (angles), which angle method is used to eliminate systematic (equipment error)?
Answer - direct and reverse
For more than a century, the _____ has been the workhorse of leveling instruments
Answer - dumpy level
The height of instrument is the elevation of the line of sight of the instrument. This is determined by adding the ______ to the known elevation
Answer - backsight
______ consists of a hollow tube with a simple spirit level that enables the user to determine a horizontal line quickly
Answer - a hand or sight level
A construction surveyor on his initial instrument setup takes a foresight rod reading of 3.78’ to a turning point 1 determining its elevation to be 4.31 ft. The surveyor proceeded to the next instrument setup taking a back-sight rod reading of 5.78 ft. to turning point 1. What is the HI of this second instrument setup?
Answer - 10.09 ft
The elevation of the turning point is determined by subtracting the __________ from the height of instrument.
Answer - foresight
Some people prefer to use the __________ for leveling because they are comfortable with its operation.
Answer - transit
Surveyors “close the level loop” by performing the following selections?
Answer - ending a level line at a benchmark
Which of the following selections will correctly satisfy the need for a rod man holding a level rod?
Answer - rock the rod back and forth slightly
In addition to being able to perform leveling operations, a __________ can be used to turn angles, and the scope can be tilted for sighting.
Answer - builder’s level
The elevation is the vertical distance above a zero datum.
Answer - true
