O R E N Z
P U L S E 5
34
In order to construct a compensated coil the coil
cable has to be laid to the figure of the shape of
an eight (8) first. The coil cable has to be fixed on
a 1m x 2m frame with a centre part which devides
the frame into two 1m x 1m frames. The cable has
to be laid and fixed twice on the center part as
this is the midle of the eight (8). This type of frame
mounted searchcoil is about 30% less sensitive
than a 1m x 1m searchcoil. This is because of the
opposite directions of the transmitted magnetic
pulses. During the receiving phase the two coils
of the eight do also work in opposite. Therefore
magnetic interferences and most ground indications
are substracted from each other and therefore
eliminated.
Interferences from radio transmitters or powerlines
will be absolutely cancelled. Highly mineralized
grounds will be indicated less sensitive than with
a 1m x 1m searchcoil. This compensated 1m x 2m
frame mounted searchcoil is of great advantage
when locating metal objects in urban areas where
interferences are often expected. This type of coil
has a very poor sensitivity for very small metal
objects. Therefore fist sized or bigger objects should
only be located. The minimum surface of a metal
plate should be 10cm x 10cm to ensure best results
when working with this coil.
Although being less sensitive, the compensated
1m x 2m coil offers very good detection depths on
any kind of ground. The maximum detection depth
is limited at 4 m.
Further informations concerning the detection
depths with different coils and mode positions
selected are recorded in chapter 11.
The coil cable is protected inside the tubes and
therefore can be used even under the worst
environmental conditions. Two adjustable carrying
straps are supplied with every frame coil.
1m x 2m universal cable coin
(compensated)
2m x 2m universal cable coil
1 winding (turn)
This is the largest frame mounted searchcoil
available with the LORENZ PULSE 5. The universal
cable coil has to be laid to a single turn on a metal
free PVC-frame and has to be fixed with tape for
example.
This particular searchcoil covers four times as
much ground as a 1m x 1m frame coil does. It
should only be used when searching for metal
objects with a surface of at least 20 cm x 20 cm
pointing towards the coil. Smaller targets will be
located less effectively than with a 1m x 1m frame
for example. This is mainly because it will become
more difficult to pinpoint those smaller objects
with the large coil. The maximum detection depth
is limited at 8 m. This can be achieved when
locating large objects like lost aircrafts or drums
for example. The 2 m x 2 m frame coil can be
carried by two persons without any carrying straps.
This is particularly useful when trying to ignore
medium sized metal objects which are smaller
than a horseshoe for example. Coins and nails will
no longer be detected when doing this. Although
being more sensitive than the 1m x 1m coil, the
2m x 2m coil should only be used when expecting
targets with a minimum surface of 20cm x 20 cm.
The large 2m x 2m coil acts as a large antenna for
mediumwave transmitters. Therefore smaller
frames like the 1m x 1m coil for example will be
of better choice when working in urban areas.
The next coil described will be less sensitive in
general but won't suffer from electromagnetic
interferences of transmitters, powerlines or the
ground itself.
