Topcon GPT-2003 Marine Instruments User Manual


 
17 CHECK AND ADJUSTMENT
17-3
10) Move the collimating point to the center of prism gradually until buzzer sound starts.
Tur ning the horizontal tangent screw to be one to two level of SIG value to adjust the collimating
point same as step 6 procedure.
11) Note horizontal angle same as step 6 procedure.
12) Calculate the average value of step 6 and 10.
[Example] Step 6 : 0°00'00"
Step 11 : 0°08'20"
Average value 0°04'10"
13) Climate to the center of prism.
Compare the reading horizontal angle and calculated average value in step 12.
[Example] Horizontal angle of the center of the prism: 0°04'30"
Difference of Average value and Horizontal reading of the center of the prism : 20"
If the difference is within 2', no problem for use.
Vertical direction conrmation (Do not move Horizontal direction).
14) Carry out as Horizontal direction conrmation.
Compare the reading vertical angle of center of prism and calculated average value.
If the difference is within 2', no problem for use.
[Example] Lower side of prism 90°12'30"
Upper side of prism 90°04'30"
Average 90°08'30"
Reading to prism center 90°08'50"
Difference 20"
If the difference is more than mentioned value, contact with your Topcon dealer or Topcon.
Prism
Reticle