Alignment; Transducer Array Flatness - Kongsberg EM 712 Maintenance Manual

Dimensional surveying and alignment
More detailed information of Kongsberg Maritime's requirements are found in the
chapter Technical specifications.
Note
Determining the relative positions and orientations of the sensors and the transducer
with high accuracy is important. This requires professional surveying done by qualified
and trained personnel using proven equipment and methods for maritime dimensional
surveying. We recommend that you use third-party consultants with well proven
experience with vessel dimensional control. Sufficient time and satisfactory work
conditions must be given to the survey work. The installation engineers from Kongsberg
Maritime are neither equipped nor trained to do dimensional surveying.
If the accuracy requirements are not met, and this is found to be the reason for a
malfunctioning system, the vessel will most likely need to be dry docked in order to
repeat the dimensional survey.

Alignment

To ensure a successful installation of the EM 712, all alignment and measurements must
be done to the highest possible accuracy.
The alignment tasks required for EM 712 include:
• Measure and adjust the transducer frames to ensure that they have been mounted
within the given tolerances.
Note
Aligning the transducer for correct installation within the given tolerances requires
professional skills. The installation engineers from Kongsberg Maritime are neither
equipped nor trained to perform the dimensional surveying, and they have no means of
verifying the results until calibration at sea has been done.

Transducer array flatness

To avoid unwanted acoustic effects caused by misalignment of the transducer elements
the transducer array must be installed with a flat surface.
It may be most practical to perform these measurements on the transducer mounting
frames before installation of the transducer modules. A final verification after module
installation is then required.
The installed transducer array shall form a plane, the following requirements apply:
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