Page 20
The Minelab Excalibur Family
Practicing the Controls
We suggest you first take some time to become familiar with how your
Excalibur responds to various metal objects.
Gather a collection of different metal objects such as a rusted nail, pull-tab,
brass button, aluminum foil, various coins, and some gold and silver jewelry.
Take the unit outside, away from known electrical devices or metal objects and
support the Excalibur so that objects can easily be moved past the coil. Ideally,
sit it on a wooden table away from nails and hinges. Then remove all jewelry
from your hands and wrists.
Ensure that the Mode Switch is in “Discriminate”.
Turn the Disc control to the most anti-clockwise position.
Turn the Sensitivity control to “maximum”, the most anti-clockwise position
without clicking into “Auto”. If excessive interference is encountered, turn the
Sensitivity control clockwise until this disappears.
One at a time, pass the test objects across the coil. The Excalibur should
“beep” on the non-ferrous objects and ignore ferrous objects.
Take note that as you pass the ferrous nail over the coil the threshold tone
disappears. As the threshold tone returns it will have a lower than normal pitch,
indicating the object ignored was ferrous.
Passing different non-ferrous objects over the coil will produce different signal
tones. Objects with high conductivity, such as silver or lead, will produce a
high-pitched signal tone while objects with lower conductivity, such as
aluminum foil, will produce a low-pitched signal tone. With experience you
will be able to use the signal pitch from an object to accurately determine the
type of object you have found before recovering it from the ground.
Now turn the Disc control progressively clockwise in steps and pass the objects
over the coil. Take note of when certain objects are rejected, this will enable
you to more accurately discriminate these objects in the field.
Turn the Disc control to the position where it ignores the pull-tab. Passing
objects with lower conductivity (such as the aluminum foil) over the coil will
not produce a signal. Take note of the threshold tone as it disappears and then
returns. It should return at a slightly higher pitch than normal. This indicates
that the Excalibur ignored a non-ferrous object.
