To do this we need to prove what are the smallest test piece sizes that can be achieved, in order to guarantee
the consumer, the maximum safety level. Get help from your metal detector provider or contractor to run the
trials, using a range of test pieces and work your way down from the larger sizes, until you get to a point where
the test piece is not picked up each and every time. It is a good idea to send the test piece through at least 30
times to prove that it rejects every time. Once you
’
ve got the test pieces that you think you should use, repeat
this again over at least 3 runs to show that it is consistent.