7 – System Specifications
7-3
© Teledyne Limited
DPN 402197 Issue 7.1
The frequency and amplitude of the tone current may affect the range measurement capability and
noise performance of the 350 system. Changes to the current and frequency will not affect the
accuracy of measurements made by the system.
The range information shown in
applies
only
where the tone current at the point of
measurement is 30mA at a frequency of 25Hz.
7.3 System Trials
This sub-section includes the practical results obtained using the 350 system at a carefully established
test site. The trials included measurements over a ±8 metre lateral offset and a vertical range of
5 metres.
7.3.1 Trials Configuration and Procedure
The test site included the largest cable loop that could be laid in the available area (see
Equipment for use in the trials procedure included:
❐
A standard Teledyne TSS HydroPACT 350 system.
❐
A hydraulic platform to support the coils of the 350 system.
❐
A loop of wire 60 metres in diameter as shown in
❐
A Teledyne TSS Tone Generator to supply the cable loop with tone current at various ampli-
tudes and frequencies.
Teledyne TSS conducted the tests using the central straight run of cable that spanned the diameter of
the loop. This arrangement reduced any effect that the current return path around the outside of the
loop may have had upon readings.
With the hydraulic platform located at the centre of the loop and the coil array positioned centrally over
the test cable, the platform could raise and lower the coils to pre-determined heights. The test
procedure also specified the cable movements necessary to simulate various lateral offsets.
