HI-PE multi-zone --- Rev.
FI 050 GB 60K10 v2_1
39
Compatibility aspects
Failure
Check and action
The
Metal Detector
gives irregular
alarms with no
people or objects
passing through it
and without
neighbouring
mechanical
structures being
shaken
High environmental
interference (display
indication
**
or higher)
Check electrical interference using the EN function
If
EN>3:
eliminate the source of interference
move the source of interference away from the metal detector, especially from the receiver
antenna RX; in particular, check that:
there are no electric power lines running near the sensitive probe.
The probe-electronics unit connecting cable runs in its own duct, and not together with power
supply cables to motors, relays or various slave devices.
screen the source of interference using an iron container.
if the source of interference can not be eliminated, move the metal detector, especially the
receiver antenna RX, away from it.
change the transmission channel (CH function) and select the value that corresponds to the
minimum amount of electrical noise. In the case of multiple installation, select different
transmission channels on the individual detectors (see section “Installation of coupled metal
detectors: synchronisation”).
set the noise limiter
NL
to 9 (not possible in the preceding situation)
decrease
DS
value (verify the compliance to the selected Security level ! ).
if the mechanical interference signal is strong (EN =0 but GN>0)
without the neighbouring
structure being shaken
, replace the electronics unit.
The Metal Detector
gives irregular
alarms when the
neighbouring
mechanical
structures move
slightly or vibrate
High environmental
interference (display
indication
**
or higher)
If EN >3, the interference is of an electrical nature; see the preceding point.
If
EN
≤
3, the interference is of a mechanical nature:
Make sure the probe is anchored securely. Avoid vibration or any other movement of the metal
detector.
make sure that no nails or screws have been driven into the transducers
move the metal detector away from the source
eliminate the source of interference :
if the source consists of
movement of large metal masses in the vicinity of the probe
:
avoid movement of the metal masses, or move them away from the probe;
if this is impossible, replace them with parts made of insulating material (glass, wood,
plastic …)
if the source consists of
modifications of the mechanical structure
which are shaken
during operation and create intermittent loops which cause strong variations in the magnetic
field:
identify and eliminate these metal structures, or, where this is not possible, insulate them.
in the case of installation near big metallic structures (distance less than 0.5 m), check
that when these latter are physically shaken (e.g. by knocking them) they do not cause
interference in the metal detector.
(*)
If the signal received by the metal detector has a high variation (
GN
≥
8
or in any
event if the display shows
more than one asterisk in its green sector
**
),
increase the stability of the system
Access system with two interlocked metal doors
If the signal does not change
noticeably when vibrations occur, try opening and closing the entry doors: if the
interference is linked to this kind of movement, the signal will vary.
Two possibilities
can be noted:
The variation is slow and follows the door movement:
in general: move the
Metal detector
further away from the door which causes the
interference
door made of metal sections: break the loop formed by the sections
metal parts which pass close to the metal detector during movement of the door:
replace with corresponding parts made of insulating material
deformation of the supporting structure: strengthen the structure or reduce the
weight of the door
The variation is fast and sudden, and occurs especially when the door slams. In
this case the variation is not due to the door but to intermittent points of contact in
the structure. See point
(*)
for the steps to take.
If the source of the interference is still not clear, please contact our Technical Department and we will give
you all the information you need
