Radiodetection PCMx User Manual

© 2021 Radiodetection Ltd 8
Distribution Lines
LFCD
An alternative frequency for congested
areas - use as ELCD
 35% 4Hz
 30% 8Hz (Current Direction)
 35% LF (640Hz or 512Hz).
8kHz Tx-25 only - locate signal only and no 4Hz
frequency for current pipeline mapping.
3.4 Output Current Selector
This rotary switch allows users to select different current
settings. The setting you use will be determined by the
type of survey that you are carrying out in terms of survey
distance and condition of pipeline coating. On some
applications, particularly high resistance applications such
as pipelines with good coating or applications where
ground conditions are not favorable it may not be possible
to achieve maximum output current levels.
Tx-150 PCM 100mA, 300mA, 600mA, 1A, 2A, 3A
Tx-25 PCM 30mA, 60mA, 100mA, 300mA, 600mA, 1A
When the transmitter is operating, the selected current will
remain at a constant level, unless the input power supply
limit is reached.
3.5 Warning lights and indicators
Output voltage
The output voltage for Tx-25 and Tx-150 is indicated by
LEDs:
 If no lights are lit the voltage is below 20V.
 If the 20V LED is lit, the voltage applied is between
20 – 40V.
 If the 40V LED is lit, the voltage applied is between
40 – 60V.
 If the 60V is lit the voltage applied is between
60 – 80V.
 If the 80V LED is lit the voltage is between
80 – 100V.
Voltage Limit:
If the 100V Red LED is lit, the unit has gone into voltage
limit - switch to a lower current setting until one of the
other voltage LED’s illuminates. Allow a few seconds to
settle between current selections.
This may happen if the resistance of the pipe or ground is
too high.
WARNING!: If the pipeline being surveyed has
coating that is known to be in good condition,
it is probable that the voltage warning LED’s
will illuminate as the current is increased.
WARNING: If the 60V/80V/100V lights are
illuminated, do not use excessive voltage or
current, as this may result in high current
density through small holidays and coating
defects. This may cause minor corrosion if the
transmitter is left switch on for very long
periods.
Transmitter status
Tx-25 and Tx-150:
Over Temperature
If the transmitter temperature exceeds its recommended
limits it will automatically shut down. The over

Radiodetection PCMx Specifications

General

Brand	Radiodetection
Model	PCMx
Category	Measuring Instruments
Language	English