THS – FI022GB2K8v3 --- V - MAINTENANCE
90
Checking environmental electromagnetic interference
The existence of interference is indicated by false alarms or by the display of several segments on the bar-graph when
the conveyor belt is stopped and there is no product in transit:
THS/STD V3.290
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THS/STD V3.290
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THS/STD V3.290
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Fig.V-9a. Example: signal well below
the threshold level
Fig.V-9b. Example: signal just below
the threshold level
Fig.V-9c Example: signal above the
threshold level (alarm).
For correct operation, the bar-graph indicator should not have more than THREE bars lit.
To eliminate the interference, the first thing to do is to identify whether it is electrical or magnetic:
1 Set parameter TX=OFF. . (NB: on model THS/MN, set the switch on the internal card of the probe power-supply unit to OFF)
2 If the interference remains the
same, it is electrical
Examples of sources of electrical interference
: electric motors, inverters, power cables, lighting
3 If the interference decreases, it
is of a mechanical nature
Examples of sources of mechanical interference
: unstable anchoring of the metal detector
(vibrations), metal masses moving in the vicinity of the probe, intermittent loops, metal
fragments in the conveyor belt.
To increase immunity to mechanical interference, adjust the AM parameter (see paragraph “Analysis mode selection criteria” ).
To eliminate sources of interference, refer to the illustrated notes in the Installation section.
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