User's Manual

15
This chapter is a summary on how to proceed with
the LORENZ DEEPMAX Z2, when locating metal,
while using the two metal classications, intensity
reading and the audio signal. It is therefore in some
cases possible to predetermine the exact position
the size as well as the kind of metal located. When a
metal object is located try to nd the place with the
strongest signal which means highest indication on
the INTENSITY bar graph and highest audio fre-
quency. Size and shape information can be derived
from the audio sound with some experience.
Small objects like single coins will be indicated with
a short and intensive signal when a small coil is
used. Coins and nails and very small pieces of metal
will cause two indications when passing them with
a frame mounted search coil (1 m x 1 m) for exam-
ple. This is mainly because those small objects are
out of the range of the large coils and therefore will
only be indicated at the edges of the frame coils
and only when they are very close to it. Large metal
objects will give an extensive signal with a longer
duration, and therefore can easily be identied.
Deeply buried metal objects will generate a weak
and slowly increasing audio sound and intensity
meter reading. Objects which are close to the surfa-
ce generate a strong and rapidly increasing signal.
Large objects will cause a signal with a long duration
especially when located with large frame mounted
cable coils. For example, a metal box 20cm x 20cm
can give a signal of up to 6m in length when pas-
sing with a (2m x 2m) coil for example. It is therefore
necessary to nd the center of a buried object by the
way of the audio and INTENSITY bar graph. This is
achieved by moving the coil from dierent directions
slowly towards the strongest indication. In many ca-
ses it is of great help to use an additional smaller coil
when pinpointing a metal. The centre of the search
coil is always the most sensitive part. When having
found the place with the strongest indication the
time delay indication will come on with a number
when the signal intensity is sucient.
A specially developed electronic circuit makes time
delay readings possible which are directly displayed
on a scale of 000 to 099. Those so called conducti-
vity readings are only known from VLF TR machines
but not from metal detectors based on the Pulse-
GBS principle. In general, these readings are based
on objects size, conductivity and permeability of
the metal and therefore named time delay readings
for simplicity. When double D coils are in use an ad-
ditional FE ferrous / NON-FE non-ferrous indication
will appear on the LC Display. Therefore, the DEEP-
MAX Z2 has to be ground balanced rst as shown in
the chapter 3 to avoid false indications produced by
the ground. Larger ferrous metal pieces will also be
indicated as being non-ferrous.
7. IDENTIFYING METAL OBJECTS
small object at the surface
large object buried deep medium size object