Depending on the orientation in which it With an x-ray machine, the less distance be required. Where something bulky
passes through, a bigger signal than the between the light beam and the detection is passing through, such as a 50lb bag
sphere may occur. point, the denser the field, resulting in of flour or sugar with 6-8 inches of
lower rates of small contaminant pick reasonably dense material, more power
With an x-ray, the detection system - up. The type of technology being used will be required to process it. On the plus
usually diodes - is underneath the light also impacts detection. Diode rays are side, these homogenous products have
beam. If the product is very thin at its typically limited to 0.8mm or 0.4mm. few density variations, so detection is
length and edge and small across the
relatively easy.
belt, even if the density is quite high, it When looking for metal contaminants of may not be detected. Equally, if it’s very all sizes, particularly low-density metals Phil ends: “Metal detectors and x-rays
thin and flat, such as stainless steel and such as aluminium, a metal detector are complimentary technologies. If, after
ferrous metal blade shapes, the total will outperform an x-ray. Yet, as the product risk analysis, you consider one is
density may be too small to detect. In aperture size increases, the x-ray races necessary, have both. A metal detector
these scenarios, a metal detector is the ahead, picking up denser metals such as should be a given and an x-ray machine
top performer. stainless steel. added to the line if there are specific
And when it comes to drilling down to The larger the aperture on a metal detail, the key detection factor is the size detector, the larger the product and more of the product in relation to the machine’s power required. Typically this is only an At Interpack 2020 (Hall 12, Stand E60),
aperture. A metal detector’s abilities increase of a few volts, rather than the Fortress will unveil how it is shaking
weaken as the aperture gets bigger, so additional kilovolts needed on an x-ray up the food inspection market with the
there’s no problem with a small detector, machine. strategic unveiling of complimentary
needs, such as potential contaminants
i.e. pharmaceutical size down to 0.15mm,
that won’t detect well.”
checkweigher and x-ray technologies.
or larger inspection ranges between If an x-ray is handling larger products,
2-4mm. larger apertures and more power will
www.fortresstechnology.com/en-uk/
FDPP - www.fdpp.co.uk 29