Teledyne 440, System Manual, Page: 22 / 256

1 – Introduction
1-4 © Teledyne TSS DPN 402196 Issue 4.1
❐ Coil mounting components
❐ Cables you will need to interconnect the sub-sea components of the 440 System.
All sub-sea components of a new installation have a depth rating to the specifications listed in Chapter
8 "System Specifications" . The main labels of the SEP and PSU also confirm the depth rating for these
components. Provided you exercise all proper maintenance procedures explained in Chapter 8
"System Specifications" , the sub-sea components will retain their specified depth rating throughout
their working life.
Refer to section 2.3 "Sub-sea Components" on page 2-5 for descriptions of the main sub-sea
components of the 440 System.
During survey operations, the sub-sea installation measures target co-ordinates. These are:
❐ The vertical range to the target (VRT)
❐ The lateral offset of the target relative to the centre of the coil array (LAT).
❐ The altitude (ALT) of the coil array above the seabed and the depth of target cover (COV). To
make these measurements, the 440 System must receive altitude information from an altime-
ter. Alternatively, where the design of the ROV allows for a constant coil height, you may con-
figure the System with this information instead.
The SEP collects the information and performs the signal processing functions necessary for the SDC
and DeepView for Windows to generate accurate survey data using a powerful algorithm developed
especially for this application.
1.4 Principle of Operation
The Teledyne TSS 440 Pipe and Cable Survey System relies on the principle of ‘Pulse Induction’ to
detect the presence of a target and to measure the range of that target from each of three search coils.
Using an adaptive algorithm the System can locate, using either two or three search coils, the position
of the target.
Refer to Appendix A "Operating Theory" for a full description of the operating theory.
The pulse induction method of target detection provides four major advantages over other systems
when used in pipe and cable survey applications:
1. It detects any type of conductive material – including non-ferrous metals such as brass,
bronze, aluminium, and light alloys.
Note that the special characteristics of 316 stainless steel
do not allow the 440 System to detect it reliably .
2. Terrestrial magnetism has no effect upon the System operation or its measurement accuracy.
3. The System can measure and electronically compensate for the local conductive effects of the
ROV, regardless of the ROV heading.
4. Simplified operating procedures built into the System give it a high degree of measurement
stability.
1.5 Warranty
Teledyne TSS Ltd warrants the 440 Pipe and Cable Survey System to be free of defects in materials or
workmanship for 12 months beginning on the date when the equipment was shipped from the Teledyne
TSS Ltd factory.