How to Use a Leveling Transit

Setting up the Transit

• 1

  Select two points, 150 to 200 feet apart. Use the tape measure to determine the actual distance between the points and use the compass to determine their directions.

• 2

  Set up the tripod legs, near one of the previously measured points. Adjust the legs so the transit is at a comfortable working height.

• 3

  Attach the transit to the tripod legs. There will be a mounting bolt that connects the transit to the tripod.

• 4

  Move the tripod and transit so the center of the transit and tripod is directly over one of the known points. This spot is known as the instrument point (IP). Use the plumb bob to establish a true position.

• 5

  Level the transit, using the leveling screws at the base of the transit and the attached bubble level. Adjust two screws simultaneously until the bubble is level. Turn the transit 90 degrees and repeat the process. Turn back to the starting point and make sure the transit is still level. Repeat as necessary until you can rotate the transit 360 degrees and it remains level.

Using the Transit

• 6

  Have the assistant stand at the second point with the graduated rod. The assistant should hold the rod level and still while the transit operator focuses on the measurement.

• 7

  Focus on the second point where the assistant is holding the rod. This second point is the back sight (BS) point. Once focused, set the horizontal angle to zero. All readings from the setup at the instrument point will be referenced in relation to the back sight point.

• 8

  Have the assistant stand at any other point where a measurement is desired. As long as he can be seen from the IP, no further setups are required. If it's necessary to move the transit to take other readings, have the assistant hold the graduated rod over top of the IP. Set up the tripod and transit over a new point, taking the same care to level the equipment. Measure the distance between the previous IP and the new IP. Take a reading from the new setup and use this as the new BS. Repeat as needed, using the IP as the BS every time a new setup is required, and measuring the distance between the two points.