Topcon GTS-823A - Manual (Page 102)

9-3
9 CHECK AND ADJUSTMENT
Vertical direction confirmation (Do not move Horizontal direction).
13) Carry out as Horizontal direction confirmation.
Compare the reading Vertical angle value and calculated value.
If the difference is within 1’ 30”, no problem for use. If the difference is more than mentioned value,
contact with your Topcon dealer or Topcon.
[Example] 90°12’ 30” 90° 04’ 30”
Average 90°08’ 30”
Reading to
prism center
90°08’ 50”
Difference 20”