How to Use Transit & Alidade

Alidade

• 1

  Place the ring on the top of the alidade, specifically on the gyro repeater. The ring will twist and lock into place.

• 2

  Determine the object to be sighted, and point the front lens at object. Use the handle as a pointer if you are having difficulty lining the lens up with the object.

• 3

  Peer through the eyepiece. Move the alidade to the right and left until the object is centered in the crosshair of the eyepiece.

• 4

  Level the alidade by watching the bubble level at the top of the alidade eyepiece. This works like a standard level, putting the bubble between the two lines to make sure the crosshairs are even.

• 5

  Read the bearing from the compass card when the object is both lined up in the crosshairs and level.

Transit

• 6

  Mount the transit on a stable surface, and level the instrument. This allows you to work from a solid base.

• 7

  Visualize the target through the eyepiece. Move the crosshairs to the top of the object.

• 8

  Write down the angle of the top of the target.

• 9

  Look through the eyepiece again, and locate the bottom of the target. Write down this angle as well.

• 10

  Repeat with the far left and right side of the target. This gives you the information that when coupled with a distance measurement allows you to calculate the size of the target.