Topcon DL-501 Instruction Manual page 115

7. Wait a few seconds for the screen to stabilize,
then read the automatically compensated F2
angles (X2 and Y2).
8. In this state the following offset values (tilt zero
point error) are calculated.
Xoffset = (X1 + X2)/2
Yoffset = (Y1 + Y2)/2
If one of the values (Xoffset, Yoffset) exceeds
±1', adjust the value using the following
procedure.
When the offset value falls within the range ±1',
adjustment is not necessary.
Press {ESC} to return to <Config menu>.
9. Press [OK] and rotate the top of the
instrument and 180° while referring to the
horizontal circle.
10. If the new correction constants are within the
range 400 ±50, press [YES] or {} to
renew the correction angle. <Config menu> is
restored.
If the values exceed the adjustment range,
select [NO] to cancel the adjustment and
restore <Tilt offset>. Contact your local dealer
to perform the adjustment.
PROCEDURE Recheck
11. Select "Tilt offset" in <Config menu>.
12. Wait a few seconds for the display to stabilize,
then read the automatically compensated F3
angles (X3 and Y3).
13. Press [OK] and rotate the top of the
instrument and 180° while referring to the
horizontal circle.
14. Wait a few seconds for the display to stabilize,
then read the automatically compensated F4
angles (X4 and Y4).
15. In this state the following offset values (tilt zero
point error) are calculated.
Xoffset = (X3 + X4)/2
Yoffset = (Y3 + Y4)/2
21. CHECKS AND ADJUSTMENTS
T i l t a d j u s t m e n t
X 0 ' 2 5 "
Y - 1 ' 3 0 "
T a k e F 2
T i l t o f f s e t
C u r r e n t X 4 0 3 Y 3 9 9
N e w X 4 0 5 Y 4 0 1
O K
N O Y E S
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