EM 122
Transducer Measurements
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. Note that it also necessary to ensure that the final transducer
array face is flat with a maximum deviation from flatness of 5 mm peak to peak
including any rotation.
Transducer heading
The heading of the transducers is measured as the average heading of the two fore-and-aft
oriented sides of each transducer arrays. Thus, the heading of the transmit transducer is
the heading of the long sides, while the heading of the receiver array is the heading of the
short sides. For the receive transducer it may be better to measure the heading of the
long sides, and then subtract 90º to achieve the correct value. The measurement accuracy
is required to be within one fifth of the beamwidth of the transmit transducer. Note
however that the measurement accuracy of the relative heading between the transmit and
receive transducers must be better than 0.1º.
Transducer roll and pitch
Roll and pitch measurements are made according to standard conventions with positive
pitch angle if the transmitter array’s forward end is above the aft end (tilts up), and
positive roll if the starboard side of the receiver array is lower than the port side.
Note that the roll and pitch angles to be measured are relative to the horizontal plane as
defined by the vessel’s coordinate system. i.e. for roll the angle that the transducer’s
y-axis have with respect to the horizontal and for pitch the angle that the transducers
x-axis have with respect to the horizontal plane. The multibeam echo sounder converts
the measured angles as entered into the installation menu to rotation angles before use
i.e. do not do such a conversion before entering them into the system.
The measurement accuracy is given in the table
Table 5
Transducer roll and pitch
Transmit transducer
Receive transducer
Roll
0.2º
0.02º
Pitch
0.05º
0.2º
Transducer position
The location of the centre of each transducer array face must be measured in the vessel
coordinate system. This centre must be measured relative to the system reference point.
Measurements must be done in the X, Y and Z directions on both transducers.
100
317669/B
Summary of Contents for EM 122
Page 1: ...EM 122 Multibeam echo sounder Installation Manual...
Page 2: ......
Page 13: ...EM 122 Figure 1 System diagram 317669 B 11...
Page 26: ...EM 122 Figure 6 EM 122 Gondola example Cd021 107 24 317669 B...
Page 27: ...Transducer arrays Figure 7 EM 122 blister and steel pipe arrangements example 317669 B 25...
Page 42: ...EM 122 B B B Plastic TX protection window 40 317669 B...
Page 46: ...EM 122 Figure 10 EM 122 Transceiver unit mounting 44 317669 B...
Page 52: ...EM 122 Figure 13 Rear view 50 317669 B...
Page 54: ...EM 122 Figure 15 Preamplifier Unit mounting 687 52 317669 B...
Page 60: ...EM 122 Figure 18 Remote Control Junction Box outline dimensions 58 317669 B...
Page 85: ...Cable layout and interconnections Figure 32 Transceiver Unit sub racks rear view 317669 B 83...
Page 88: ...EM 122 Figure 34 Preamplifier underneath view 86 317669 B...
Page 128: ...EM 122 Ice window Figure 59 TX Ice window 126 317669 B...
Page 129: ...Drawing file Figure 60 RX Ice window 317669 B 127...
Page 131: ...Drawing file Preamplifier Unit Figure 62 RX Preamplifier Unit internal cabling 317669 B 129...
Page 132: ...EM 122 Figure 63 RX Preamplifier Unit internal cabling 130 317669 B...
Page 154: ...2013 Kongsberg Maritime...
