Teledyne 440 - 7 Operational Considerations; 7.1 Operating Performance; 7.2 Sources of Error; 7.2.1 ROV Handling

Contents
DPN 402196 Issue 4.1 © Teledyne TSS v
8.2 Performance ....................................................................................................................... 8-5
8.3 Update Rate ....................................................................................................................... 8-9
9 Maintenance .............................................................................................................................. 9-1
9.1 Circuit Description .............................................................................................................. 9-1
9.1.1 Power Supply Pod ...................................................................................................... 9-2
9.1.1.1 Power Supply PCB.............................................................................................. 9-2
9.1.1.2 Filter Assembly.................................................................................................... 9-3
9.1.2 Sub-sea Electronics Pod ............................................................................................ 9-4
9.1.2.1 Main Board.......................................................................................................... 9-4
9.1.2.2 Driver Board ........................................................................................................ 9-4
9.1.2.3 Analogue Board .................................................................................................. 9-4
9.1.3 Communications Loop ................................................................................................ 9-5
9.2 Disassembly and Reassembly ........................................................................................... 9-5
9.2.1 Surface Display Computer ......................................................................................... 9-6
9.2.2 Sub-sea Installation .................................................................................................... 9-6
9.2.2.1 Sub-sea Electronics Pod..................................................................................... 9-6
9.2.2.2 Power Supply Pod............................................................................................... 9-8
9.3 Fault Identification .............................................................................................................. 9-9
9.3.1 Fault on Single Channel Only ................................................................................... 9-11
9.3.2 Current Loop Communications Failure ..................................................................... 9-13
9.3.3 Altimeter failure. .......................................................................................................9-17
9.3.4 Unexpected Signal Variation During Normal Operation ........................................... 9-20
10 System Drawings .................................................................................................................. 10-1
10.1 Electrical Drawings ......................................................................................................... 10-1
10.2 Mechanical Drawings ................................................................................................... 10-16
A Operating Theory..................................................................................................................... A-1
A.1 Pulse Induction .................................................................................................................. A-1
A.2 Waveform Measurement.................................................................................................... A-2
A.2.1 Timing ........................................................................................................................ A-3
A.2.2 Derivation of Signal Voltage....................................................................................... A-4
A.2.3 Seawater Rejection.................................................................................................... A-4
A.2.3.1 Introduction ........................................................................................................ A-4
A.2.4 Compensation: How it Works..................................................................................... A-5
A.2.4.1 Background Compensation ............................................................................... A-6
A.2.4.2 Active Compensation......................................................................................... A-6
A.2.4.3 Checking the Rejection...................................................................................... A-8
A.2.4.4 Rejection Parameters ........................................................................................ A-9
A.2.4.5 Background Noise Profile .................................................................................. A-9
A.2.5 Trenching Vehicles .................................................................................................. A-10
A.2.6 Limitations................................................................................................................ A-10