Detecting Techniques and Tips
(continued)
20
DD
Searchcoil
Concentric
Searchcoil
Illustration 1
Iron Masking Tip
To prevent an iron object from "masking" out the
signal of an adjacent good target, use just enough
discrimination to barely reject the iron trash
(e.g. small
nail, as seen in Illustration 1)
. This will allow you to detect
the coin and nail together
(see Illustration 2)
and not
miss/mask a good target.
Illustration 2
In this illustration,
Apex
is
operating in Zero Mode with
two pixels of iron eliminated.
This nail registers from 18 to 24
on the Digital Target ID scale. To
eliminate the nail from detection,
notch three more pixels of iron.
In this illustration, the same
iron nail is laying above a gold
coin. With five pixels of iron
now discriminated, the nail itself
would not be detected; however,
the two objects (nail and coin)
have a combined conductivity of
more than 25.
Therefore, the gold coin is detected due to the combined conductivity
being higher than that of the discriminated target (nail) alone.
Isolating Adjacent Targets
The narrow detection field of
Apex
’s Viper DD
searchcoil allows better separation of adjacent targets
versus a similar size concentric searchcoil. Use narrow
swings of the searchcoil in trashy areas to isolate good
targets amongst the trash.
