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TM30 User Manual v. X1.0
5.3 Adjusting receiving gain
Receiving gain (sensitivity) can be adjusted with the 3-step
GAIN
adjustment and
GAIN
LED
s display which gain setting is on. It is recommendable to use gain, which makes the
Level bar
height to be approx. in the middle; that way changes in signal strength are
easiest to notice.
Level bar displays target location either as maximum signal (e.g. wire pairs) or minimum
(e.g. cable tracing). Audio signal strength from the
speaker
is dependant of the
GAIN
setting too.
6. Introduction to operating modes
Tracing a cable or wire or another object is always based on detecting the electric field
(capacitive tracing) or the magnetic field (inductive tracing) of a conductive object. These
basics are common to all tracing so understanding them is vital.
6.1. Open wires mode and capacitive antenna
As the name suggests,
Open wires
mode is intended for close range tracing of open
(disconnected) wires and pairs and other conductive objects. Wires that are under a
shield or deep inside other structures can’t be traced with this mode.
Open wires
mode
works relatively close to the target, usually less than 20cm, and it is best with wire & pair
identification and tracing.
Depending on the situation, transmitter is connected either to the traced wire pair or
between one wire and grounding. When the receiver nose tip (i.e. the capacitive
antenna) is close to the target,
Level
bar rises accordingly and loud signal can be heard.
The direction of the nose has almost no significance, as the shape of the capacitive
antenna sensitivity area is spherical (ball shaped), as shown in below figure. Figure
shows also the typical shape of the capacitive field generated by a single wire.
Figure 6.1.
Capacitive antenna sensitivity area shape in Open wires mode (left)
and typical shape of a capacitive field (right).
