Instruction manual
Now, if you consider that piece of ferrite I
mentioned, and think about those deep pieces
of iron you dug this summer (anticipating a
silver dollar because they read a +48 ), and toss
in this theory of circular discrimination, you get
an idea as to how it happened. You dug a piece
of iron that provided a TID of +48. Did it read a
negative number after it was dug up? Probably.
Did the X-TERRA mislead you, making you think
it was a highly conductive target when it was
still in the ground? Yes, it can be misleading.
But based on the information available, the
X-TERRA made its “best guess” as to where
to position that target in its eld of “circular
discrimination”.
Just as a dime reading 36 can bounce to a 38 under given conditions, a piece
of iron can bounce between -8 and +48. And, since the 705 we are discussing
does not have any notch segments between the adjacent notches of +48 and
-8, the iron will identify with the one it is most closely aligned to. Factor in the
ground conditions, and you can see how that deep old iron can fool you into
thinking it is a silver dollar.
My theory is, regardless of how many notch segments could be added
between the -8 and +48, there will always be targets that “fall” between the
most negative TID and the most positive TID. The best solution I have to oer
is to use the tips I’ve tried to provide throughout this eBook, and listen more
intently to the audio response made by these wrap around signals. When
working the coil over the target, iron tends to provide both high tone and
low tone harmonic signals.
From a strictly technical point of view, I don’t believe the wrapping of ferrous
and non-ferrous is truly circular, or 360 degrees. I believe it to be semi-
circular at 180 degrees. However, in an attempt to not make my explanation
more confusing, I used the example of a compass, and the terms circular and
360 degrees, instead.
My Circular Discrimination Theory
78Understanding your X-TERRA - Technology