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8
Using the vLoc-9800
8.3.3
Induction
This is used when no connection via direct connection leads, or coupler is possible. If no connection leads or
clamp are connected to the transmitter, it will automatically select "Induction" mode.
An induction loop is fitted inside the handle of the transmitter. The transmitter must be placed over the target
cable with the handle over and in line with the target pipe or cable. The induction loop is tuned to operate at
specific frequencies. Only these frequencies can be selected when in "Induction" mode.
Do NOT place the transmitter on a manhole cover, or any other such metallic object, as that object will shield
or soak up the signal resulting in little of no signal being induced in the target line.
When using the "Induction" mode to apply a signal to a line, ensure that a minimum distance of 50ft (20m) is
maintained. This is because the transmitter will transmit signal through the air which will interfere with signals
from the cable, resulting incorrect information.
8.3.4
Searching (sweeping) an Area
In any given area, it is likely that buried pipes and cables are not parallel to each other, frequently they will
cross the area being searched at a variety of different angles and depths. As the response of locator
antennas is directional, it is important to search the area in the same or similar pattern as below. This orients
the antennas in a way that will locate any signals being radiate from the buried line. Once a response is
found, then trace and pinpoint the line and mark. Searching an area in this way is generally (but not
exclusively) done in the "Peak" mode using passive locating.
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