5 Loc-10TxSIS Transmitter
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“Induction” mode is generally used when no access is available to make a direct connection, or a clamp
connection. When using induction it is very likely that the signal being induced onto the target line will also be
induced onto other lines in the area, and onto above ground features such as wire fences. This can influence
the accuracy of the location, depth and current measurements. “Induction” mode is also the least efficient
way of applying the transmitting signal to the target line. The distance located with “Induction” mode is
generally much less than that achieved with a direct connection or clamp connection. “Induction” mode
generally works better in higher frequencies, 33 kHz, 65 kHz and either 83.1kHz or 200kHz (depending on
region). The advantage of induction is that no access is required to “connect” the transmitter, making it a very
quick process. The antennas on the transmitter are tuned to induce specific frequencies or range of
frequencies. Therefore only a limited number of frequencies can be selected in “Induction” mode.
NOTE
For accurate location and depth measurement the locator receiver should be used
no closer than 50ft (20m) from the transmitter.
5.3.2
Direct Connection Mode
By plugging in a connection lead to the output socket, “Direct connection” mode is selected. An icon
confirming this is shown on the display. The icon flashes when the transmitter is transmitting. The direct
connection lead consists of two cables, one (red clip) must be connected to the conductor being located, the
other (black clip) to a suitable ground (a ground stake is provided with the transmitter). An auxiliary ground
lead is also supplied. If the auxiliary ground lead is used, the ground clip of the connection lead (black clip) is
attached to one end of the auxiliary ground lead.
Wherever a direct connection can be safely made without the risk of injury, damage to customer’s plant, or
the transmitter, it is the best way of applying the transmitter’s signal.
The coupling of the transmitted signal to other pipes and cables in the area will be much less than with
induction, although where commonly bonded systems are encountered – coupling cannot be avoided.
The positioning of the ground connection can also influence the degree of coupling experienced. Ground
connections generally should not be made to other pipes or cables, or above ground metallic structures such
as wire fences. In general the lower the frequency is, the further the signal will travel, and the less signal
coupling will occur. The most common frequencies used for direct connection are between 512Hz/640Hz and
8 kHz.
Regulations in many countries require that power output is limited above certain frequencies. The Loc-
10TxSIS enables frequencies below 45 kHz to be transmitted using as much as 10 watts output, but
frequencies over 45 kHz are restricted to 1 watt. Using direct connection and the higher power at the low
frequencies helps significantly in achieving greater location distances. Direct connections should not be made
to cables carrying greater than 35 volts (or as your safety practices allow). The transmitter is protected
(250Vfuse) from stray currents that may exist on the target line.
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[email protected] | 13309 Beach Ave. Marina del Rey, CA 90292 | Phone: 800-WCT-PROD (800-928-7763) | Fax: 310-306-9343
