Spectra Precision Survey Pro v5.3 - Manual (Page 81)

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Running the 2 Peg Test
The 2 Peg test is used to check the collimation error of an automatic level
instrument. This test can be used for electronic automatic levels and manual
automatic levels. The test will compute the error, which can then be used to
adjust the horizontal cross-hair of the instrument.
1. Position two rods 50 to 90 meters apart (165 to 300 feet).
2. Pace off the distance between the rods and set up the level midway
between them. (The placement of the rod over Point B can be adjusted after
shooting Point A.)
3. Carefully level the instrument. You should be able to rotate the instrument
180° around its vertical axis without the bubble moving away from the
center.
4. From the main menu, tap
Survey > 2 Peg Test.
5. Tap Take Shot. You are now prompted to take each set of shots to the rod
over Point A. Once each shot is completed for the number of sets entered
in the
Level Settings screen, you will return to the Peg Test screen.
6. Turn the instrument to the rod over Point B.
7. You can optionally tap Check H Dist to verify the instrument is centered
between the two rods.
The distance to Point B will be measured and compared to the horizontal
distances previously measured to Point A and a come/go distance will be
provided so the rod at Point B can be moved to equal the horizontal
distance to Point A prior to taking the shots that will be used to compute
the error.
8. Tap Take Shot. You are now prompted to take the required shots to the rod
over Point B. Once completed, the Peg Test screen will open with a new
graphic showing the next instrument setup.
9. Move the instrument as close as possible to the rod over Point A where a
shot can still be taken to it. This is typically about 3 meters (10 feet) from
the rod.
10.Tap Take Shot. You can now take the required shots to Point A from the new
instrument setup.
11.Once complete, turn to Point B and take the required shots to that point.
12.After the final shot is taken, the Peg Test Results screen will open showing
the details of the shots taken and the computed error.
13.Tap to close the results screen.