Sokkia SDL30 Operator's Manual page 38

5 Measure the foresight.
The instrument calculates the height
difference ΔH relative to the back-
sight, and displays the result.
6 Select "Yes" to accept the point
number, attribute and measurement
value.
The result is saved.
7 Press .
A message asks whether you want to
change the instrument position.
8 If moving the instrument, select "Yes".
In step 5, the measured foresight is
recorded as turning point (TP) height
difference.
9 Transfer to the next instrument position
and repeat the measurements from
step 3.
The height difference measured at step
5 is displayed as the height difference
of the backsight (TP).
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