33
b) Metal differentiation (discrimination)
Each metal type exhibits its own characteristic phase shift, which makes it possible to distinguish between different
types of metals. Using phase shift to identify different types of metals is known as discrimination. Metal objects with
inductive resistance, i.e. large objects made of good conductors (gold, silver, copper) exhibit a larger phase shift.
Metal objects with ohmic resistance, i.e. small objects made of poor conductors exhibit a smaller phase shift. See the
following list for the approximate conductivity values of different conductors (metals and electrolytes).
Material Electrical
conductivity (S/m)
Material
Electrical
conductivity (S/m)
Material
Electrical conductivity
(S/m)
Silver
63.01 × 10
6
Gold
45.2 × 10
6
Calcium
29.8 × 10
6
Nickel
14.3 × 10
6
Platinum
9.66 × 10
6
Zinc
16.6 × 10
6
Copper
59.6 × 10
6
Aluminium
37.8 × 10
6
Cobalt
16.7 x 10
6
Iron
9.93 × 10
6
Tin
9.17 × 10
6
Salt water
4.788
Fresh water 0.0005 - 0.05
11. Operation
a) Functions and display
Push button (reset) (9)
Together with the
TUNE
dial (5), this push button is designed to configure/
adjust the zero position of the display pointer.
DISCRIMINATION
dial (15)
Use this dial to configure the discrimination threshold for different metals.
MODE
dial (16)
Use this dial to switch on the metal detector and select the mode. There are
three modes: "VLF", "TR1" and "TR2".
"VLF" mode is the default setting.
"TR1" mode is the primary metal detection mode. This mode distinguishes
between different types of conductive objects, such as gold (non-ferrous
metal) and steel (ferrous alloy) and indicates the metal type on the analogue
display (21).
"TR2" mode is used for a more accurate analysis of objects detected in
"TR1" mode. It distinguishes between objects such as gold and aluminium
and indicates the metal type on the analogue display (21).
GROUND
dial (7)
This dial allows you to configure the metal detector for different types of
surfaces to improve the search results.
TUNE
dial (5)
The
TUNE
dial (5) is designed to tune the detection probe (1) to the
electronic components in the control unit (22). It corrects the zero position on
the analogue display (21).
VOLUME
dial (13)
This dial adjusts the volume of the audio signal (speaker and headphones).
