White’s Electronics TDI - Manual (Page 26)

6 PulseScan TDI Owner’s Guide
# - TURN ON AND ADJUST THRESHOLD
Turn the power switch On and adjust the threshold to a faint hum, as noted
under “Description of Controls”. The threshold hum should be set just above the
chatter point so that the hum is reasonably continuous - faint, but steady.
# - GET FAMILIAR WITH A TARGET SOUND
Put a target on the ground to become familiar with the response of the detector.
Use a nickel or a gold nugget. Please note that the Pulsescan TDI is a motion
detector which means that as the search coil passes over the target you hear a
response only when the search coil is kept in motion. Stopping over the target,
the signal will disappear and you only hear the threshold hum.
Be sure to use a reasonably sized target, so that you can get a better idea of
what a target sounds like. Note that the target audio will get louder, and the pitch
will rise as the search coil passes over the target. Now is a good time to adjust
the volume on the headphones so that you can hear a good response from the
target while being able to hear the continuous hum of the threshold when no
target is present.
Keep the search coil flat to the
ground as you are sweeping
from side-to-side.
Sweep the search coil from side-
to-side overlapping each pass.