Leaders in Pipelin
e Survey Systems
C
C
C
-
-
-
S
S
S
C
C
C
A
A
A
N
N
N
2
2
2
0
0
0
1
1
1
0
0
0
SYSTEM MANUAL Version 6.03i
58
8.11. Orientation of Detector to Pipe Axis
The C-SCAN Detector uses the vector sum of the outputs from the antenna coils so that
variations in the horizontal angle between the axis of the instrument and that of the
pipeline are compensated for (although it is good practice always to approach the pipeline
from the same side and approximately at right angles to its axis). Although the main
source of potential operator error is eliminated, there is still the necessity to ensure that the
axis of the Detector antenna is perpendicular to the pipeline in the vertical plane. This is
not a problem in normal conditions where the pipeline is effectively horizontal, and the
instrument vertical. But where a pipeline has been installed on a steep slope, and is
parallel to the ground surface it is important that the Detector is held with its axis
perpendicular to the ground (i.e. not vertical). If the Detector is used vertically in such a
situation, the ‘effective length’ of the antenna is reduced (by the Cosine of the angle),
leading to errors in the derived information.
