Bench Tests
You should conduct bench tests to become more
familiar with the
Axiom
’s signals and operation using
different Modes, Speeds, and Audio Types. Suggested
test items include:
• Various size gold nuggets or gold rings. Note: In the
absence of gold nuggets, a U.S. nickel or small
bronze coin are good imitators of the response
characteristics of a similar size nugget.
• Coins or relics you expect to find in your search area.
• Various size iron targets for testing the Iron Check
feature.
Note:
By their nature, high performance pulse
detectors, like the
Axiom
, are often very noisy indoors
or anywhere near developed areas due to numerous
sources of electromagnetic interference (EMI). It is
therefore best to test the detector outdoors, away
from common EMI sources (e.g. power lines, electrical
equipment, buildings, etc.). Tests should be performed
with the searchcoil completely stationary and several
feet away from any large metallic object.
Basic Testing
Begin passing various metallic targets from side-to-
side across the bottom of the searchcoil. Pass the
targets both near and far from the coil to hear how
proportional audio sounds (i.e. loud for strong signals,
faint for weak signals).
Tone Polarity Test
Begin passing various metallic targets over the
searchcoil to hear the response using both Audio 00
(PWM audio) and Audio 01 (VCO audio). You will notice
that poor conductors (i.e. small nuggets, nickels, small
bronze coins, etc.) will produce a high tone followed
by a low-tone echo. Good conductors such as large
nuggets, copper and silver coins, large bronze coins,
etc. should produce a low tone followed by a high-
tone echo.
A target on the borderline between a poor and
good conductor may fluctuate multiple times between
high and low tones to indicate a borderline conductor.
For pulse induction detectors, iron can and will read
everywhere on the tone/conductivity scale, which
is greatly affected by the iron object’s size, shape,
orientation, and condition. Small iron is often a high
tone (just like low conductors) and large iron is often a
low tone (just like good conductors), but not always.
Iron Check test
Iron Check only works when using a DD searchcoil.
Press and hold the IRON CHECK button and wait for the
double beep before scanning targets. Continue to hold
the IRON CHECK button while quickly scanning your
test targets back and forth across the coil.
Notice which iron targets produce the very low-
tone growl/grunt sound and at what distances. Notice
that many iron targets will create a different response
when their orientation is changed. Since the
Axiom
’s
Iron Check function is conservative to help ensure that
small/weak good signals are not misidentified as iron,
small iron targets may not identify as iron.
Test both ferrous and non-ferrous targets at various
depths to become familiar with Iron Check’s capabilities
and limitations.
Sensitivity test
Increase and decrease Sensitivity to see how
detection depth and noise are affected. For example,
higher Sensitivity increases depth and possibly
increases noise.
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Summary of Contents for Axiom
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