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TM30 User Manual v. X1.0
6.3 Cable route mode and rod probe
Cable route
mode is intended for tracing cables and tubes even underground.
Also
Cable route
mode is based on inductive
tracing in which a magnetic field created by a
current running in a wire is detected with the
TMR30
rod antenna. Stronger current gives
higher signal and longer detection distance.
There is however a precise minimum point right
above the right wire or cable.
Rod antenna is very unilateral, i.e. it has very
sharp and narrow sensitive area pointing to the
direction of the nose, as shown in the figure to
the right.
Figure 6.2.a. The sensitive area of rod probe in Cable route mode.
When using
Cable route
mode it is recommendable to keep the receiver all the time in
upright position towards the target, as in the two figures below. Pendulous moving
(rightmost figure) may detect minimum spots caused by return currents or other cables
and hence mislead the user to wrong conclusion.
Figure 4.2.b. Right and wrong ways to use receiver in Cable route mode and
corresponding field shapes and the minimum spot of a straight wire.
6.4 Monitor modes
TMR30
offers three monitoring modes to identify communication signals on wires and
signals generated by e.g. electric appliances. These modes use the capacitive antenna,
so the most sensitive area is at the tip of the
TRM30
nose. The direction of the nose has
little significance, as the capacitive antenna sensitivity area is spherical (ball shaped)
with no minimum spots etc, as shown earlier in figure 6.1.
Powerline
mode is intended for tracking 50-60Hz mains wires e.g. inside walls and also
to identify phase connector of a wall socket like with a mainstester.
Audio freq
mode monitors audio frequencies up to 10kHz on wires or e.g. on electric
appliances. As audio signal fields are by nature very weak,
TMR30
nose must be as close
to the target as possible.
High freq
mode is for tracing frequencies over 10kHz on wires or terminals. E.g. DSL
signals can be detected with this mode.
