NA720/NA724/NA728/NA730-1.0.1en
Measuring
18
Wanted:
Height difference of several
reference points.
The required accuracy is
usually not very high
with such measurements.
Nevertheless, from time to time
read the staff on a stable
intermediate point (reading must
remain the same).
Area levelling
Procedure:
1. Set up instrument centrally
between the desired points.
The instrument telescope
may not be below the highest
measured intermediate point.
2. Set up staff vertically at
reference point A.
3. Aim on staff and read and
take down height (=backsight
to known point).
4. Set up staff vertically at
point 1.
5. Aim on staff and read and
take down height
(=measuring intermediate
point, intermediate sight)
6. Repeat steps 4 and 5 for
additional intermediate
points.
Height =
Height of station point
+ backsight (A)
- intermediate sight
Point
No.
Interm.
sight
Height
A
592.00
R1
+2.20
⊗
594.20
S1
-1.80
592.40
S2
-1.90
592.30
S3
-2.50
591.70
S4
-2.30
591.90
NA-29
R
S1
A
1
2
3
4
S2
S3
S4
7. The height of individual points
are:
Example of booking:
⊗
=
Instrument horizon
