Discrimination - White's TREASUREmaster Owner's Manual

Discrimination

The Treasuremasters have the ability to accept or reject metal
types based on their conductivity and/or electrical phase.
Target conductivity/phase is indicated on the display VDI scale
(Visual Discrimination Indication) with a VDI reference number.
By learning what targets consistently indicate specific VDI num-
bers, you can be sure to accept or reject the different target
VDI ranges that interest you.
Many types of targets share similar VDI number ranges. For
example gold jewelry of varied sizes/ types shares the same
VDI number range as aluminum of varied sizes/types. Deeper
depths suggest the target being heavier gold; shallow depth
indications suggest the target being lighter-weight aluminum.
However, to find all the gold jewelry, digging lead, pull tabs
and screw caps is to be expected.
Non-target metals (iron) often produce some beep, different
from an accepted good target. In most cases, iron will produce
a broken or inconsistent tone whereas an accepted good
target produces a more consistent beep. The display can help,
but an inconsistent tone is most likely a rejected target. If you
have trouble recognizing these inconsistent beeps and displays,
find the sweep speed that enhances the rejection sound to the
point you can recognize it, compared to the sound of a good
target. Accuracy is greatly increased sweeping the center
of the target. Pinpoint (press /X) and "x" the area with the
"heel-and-toe" method from Quick Start (strongest beep and
shallowest depth indicate center), return to Discrimination
(press /X again), then pass the search coil over target center
and note the sound and display indication.
When a metal target doesn't indicate as expected, peculiari-
ties within that metal's alloy mix (metal types) are usually to
blame. For example, as steel bottle caps age, the iron dete-
riorates and the better (non-iron) alloys remain and become
prominent. Very old bottle caps are likely to indicate as a
quarter. The longer they are in the ground, the more the iron
dissolves and the stronger/better the non-iron looks to a metal
detector.
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