Spectra Precision Survey Pro v4.6 Ranger User Manual - Manual (Page 207)

Leveling
197
2 Peg Test
The 2 Peg Test is used to check the collimation error of the
instrument. The test will compute the error, which can then be used
to adjust the horizontal crosshair 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, select Leveling > 2 Peg Test .
5. Tap Take Shot. The Leveling Shots
screen will open where you will be
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. The Leveling Shots screen will open again
and prompt you 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 setup.