Minelab X-Terra 505 Manuel d'instructions télécharger pdf (Page 68)

To Dig, or Not to Dig?

3. Consistency of TID

Having located a target with a consistent location and a consistent audio

tone, it is time to check the TID. At this point, I already know if I am going

to be digging this target, based on the location and sound. But if those

two things “pass my test”, I’ll check the TID primarily to see if it is going to

be copper, silver, nickel or gold when it is exposed. As I sweep back and

forth across the target again, I take notice of the display.

I know this comment will create some disagreement, but I am convinced

that in my moderately mineralized soil, (and when my detector is

properly setup) single coin targets, lying at, will not produce a TID that

varies by more than two notch segments. That means if I get a TID of 38

and it occasionally reads a 36 or 40, I’m looking in the hole for a silver

dime. Notice I said that the numbers would be consistent IF there are no

adjacent targets and the target is laying at. And I am talking about a part

of the country where the mineralization levels are relatively low.

When there are adjacent targets, the TID can become skewed if those

adjacent targets are larger than the “desired” target or shallower than

the desired target. Even if they are the same size and depth, if they are in

close proximity, the TID can be misleading. Typically, a coin on edge will

give a strong signal response as you pass the coil in the same direction as

the “length” of that edge. But will produce a broken audio, a double tone,

or no audio at all, when passing the coil perpendicular to the top edge

of that coin. As well, the TID for coins on edge will change when swept

from varying directions. The reason for these audio and TID variances

is because the detection pattern of a metal detector is penetrating the

surface area of the target with its electromagnetic eld.

Briey stated, the eddy currents induced back to the receive circuit on a

at coin are of a much dierent phase than those from the edge of that

same coin. For those that have doubts, try air testing some coins. No

mineralization, no adjacent targets and make sure you hold them at. I

guarantee that they will provide a solid tone and a stable TID. But if you

don’t have your X-TERRA set up properly, all bets are o.

Understanding your X-TERRA - Practical Detecting

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shhshh 23 Jan 2024 | 16:17:44

Minelab X-Terra 505 Manuel d'instructions Page 68