Metal Detection: Comparison Versus X-Ray Technology

In the past few years there has been an increased level of interest in the use of x‐ray technology for the inspection of food products in order to detect foreign contaminants. These machines have been available for decades and are not an emerging technology, in fact the discovery of x‐rays dates back to the late 1800’s – making metal detection a relative newcomer.

In order to understand the capability of x‐ray inspection technology, it is important to look at the basic concept of x‐rays which are capable of passing through low density substances but are blocked by higher density materials. It is worthy to note that only density differences are detectable, and density should not be confused with hardness. Many contaminants that might be considered easily detectable with an x‐ray system are not.

Contaminants such as wood, plastic, nut shells, fruit pits, etc., are not detectable. Even glass, rock and bone detection is limited in many cases.