D2 - LT #1 Electronic Layout Equipment Flashcards
Which instrument uses a magnifying glass to read the angle measurement?
Open-Faced Transit
A transit or theodolite can be used for?
Levelling and laying out angles horizontally and vertically
How are the angle readings viewed when using an electronic theodolite?
on an LCD in degrees, minutes & seconds.
How large are the graduations on the horizontal circle for a level transit?
Horizontal circle is graduated in 1 degree divions.
How many minutes are in one degree?
60 minutes
When an instrument does not have an “optical plum met”, what can be used in its place?
Plumb bob
The horizontal circle eyepiece is used to:
Take angular readings
Which type of instrument may incorporate the use of a micro-dial knob?
A theodolite
Vertical angles on an electronic theodolite may be read as:
DMS or % of slope
BONUS: Horizontal ALWAYS DMS
When setting up an electronic theodolite on stable ground, it’s important to ensure that:
The compensator is turned on.
How many seconds are in a circle?
1 296 000
What is the smallest increment of angular measure that can be read on transit with a vernier?
20 seconds
How many divisions would be on one side of a 30-minute vernier that can be read to 30 seconds?
60 divisions
What type of transit uses a horizontal circle eyepiece?
A closed face transit & theodolite
Is a magnetic compass used when laying out a building?
No
Which clamp is tightened to make the horizontal circle fixed to the ground?
Lower clamp
What is the term used to define the keys on the keyboard of an electronic theodolite that have more than one fuction?
Soft keys
When using an electronic theodolite, what is used to plumb the instrument over a point on the ground?
Laser plummet
What is the term used to define the keys on the keyboard of an electronic theodolite that have more than one function?
Soft keys
What is the term used to describe the angle formed between true north and magnetic north?
magnetic declination
Describe the level transit
1) Full horizontal circle & partial vertical circle
2) Uses a vernier scale that allows them to be read to the nearest 10 minutes of arc.
3) The vertical circle allows readings to angle of about 45 degrees
Describe the transit
1) full horizontal and vertical circles
2) equipped with an accurate vernier accurate to one minute of an arc or less
Describe the theodolite
1) full horizontal and vertical circle
2) scale to measure angles uses a micro-adjustment allowing reading up to one second of an arc
Describe electronic theodolite
1) No scales
2) Readings displayed on LCD, software is set by software
3) Angle readings of fractions of a second can be displayed but 5 seconds is the average
Open-faced transit is called open faces transit why?
The horizontal and vertical circles are visible from the outside of the instrument.
What is the difference between open-face transit and closed-face transit?
the vernier and horizontal circles are enclosed within the body of the instrument.
What does the eyepiece on a closed-face transit do?
View the angle measurements:, and eliminates the need for a magnifying glass.
BONUS: Eyepiece on the horizontal and vertical circle readers and the telescope focused by turning the eyepiece
What does a soft key (on a theodolite) refer to?
A key with multiple functions
What does a transit use for setting the vertical axis over a known point?
Plumb bob or an optical plummt
What does a theodolite use for setting the vertical axis over a known point?
An optical plummet or a laser plummet
What does an electronic theodolite use for setting the vertical axis over a known point?
Optical plummet or laser plummet
What is the allowance of accuracy on an EDM?
1-3 mm is allowed for each 1000 m measured.
EX over 7000, 21 mm margin of error is permitted
