Hi all,
I just wanted to add some notes to this intersting discussion. To be up front and declare an interest - as one of the world's largest
X-ray system suppliers many of the contaminants we have seen in cans comes from the incoming raw materials.
We have run some extensive on site trials using an Eagle Tall
X-ray from my company; Smiths Detection, Product Inspection Division -
www.smithsdetectionpid.com For canning applications - alongside contaminant detection one added value we see is that the system can be used as a high speed checkweigher - before the retort and checking dry ingredients. The checkweighing uses the
X-ray image to calculate the mass from the image. There are no moving parts so speeds can be upto 800 cans/minute and the cans can be literally touching. The results we have seen are better than +/- 0.5g for repeatable accuracy.
Stainless steel detection is from 0.8mm at 50% Probablity of Detection (POD) to 1.0mm stainless steel at 100% POD. In addition the systems also find stone down to 2.5mm (this depends on the density of course) and glass at similar levels (inside steel or alu cans). We also have a QuadView system, a four beam
X-ray system for finding glass shards in glass containers, this of particular interest to baby food processors.
Smiths Detection has direct PID offices in the US and the UK where we have demonstration systems avalailable.