Loma IQ3+, User Manual

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Safety First
13
Real contaminants are rarely spherical so may produce different signals depending on their
orientation as they pass through the aperture. Wire contaminants are the most dramatic example of
this as shown in the diagrams below.
A common solution to this problem is to use two metal detector heads positioned at different angles
across the conveyor belt so that the contaminant is presented at a different angle to both detectors.
Testing Metal Detector Performance
Regardless of how sophisticated and reliable a metal detector is, it is only as good as the frequency
and thoroughness of the testing programs supporting it.
Testing and recording are essential components of any HACCP system and must be supported by
clearly documented testing procedures that are communicated to all staff using the detector and are
monitored and reviewed on a routine and regular basis to ensure compliance with customer and
legislative requirements.
Test Frequency
Intervals between tests need to be short enough that if a fault is found, products potentially affected
have not left your premises and can be identified, recalled and retested. Once again, if your company
is a private label manufacturer, ensure that you agree upon any variation you make to testing
procedures, in writing, with your retailer customers.
To facilitate effective testing, all of Loma's Metal Detectors have an integral Performance Validation
System (PVS) feature. This feature can be set up to automatically prompt the operator to carry out the
required test at a pre-set interval.
The screenshot below shows the Main Run screen with the performance validation countdown timer
displayed, using the default interval of 6 minutes, to assist with HACCP compliance.