bag means, at some point, the count didn’t add up the way it should have.
Decoding “Ferrous 25mm BST” and the Cert Number
The writing on the disc isn’t random. “Ferrous” means
the test metal contains iron, so it’s magnetic. Detectors are typically checked with three types of test metal: ferrous, non-ferrous like brass, and stainless steel, since each type behaves differently in the detector. Ferrous is generally the easiest to catch, which is exactly why it’s part of a standard test set.
The “25mm”
There’s more to discover. Continue to the next page for the rest of this article.
