Metal detection or X-ray?
We build metal detectors. The answer is still not always a metal detector, and there is no point pretending otherwise. Here is the honest comparison.
The short version
A metal detector finds metal. X-ray inspection finds anything denser than the product — metal, glass, stone, ceramic, bone and dense plastics — and can also check fill level and missing components.
But X-ray is markedly more expensive to buy and to run, requires radiation shielding and trained personnel, and is worse than a metal detector at finding small pieces of stainless steel in thin, light products. For most food producers a metal detector is the right choice, and it is what the standards assume.
| Aspect | Metal detector | X-ray |
|---|---|---|
| Finds metal | Yes — ferrous, non-ferrous and stainless | Yes, depending on density and size |
| Finds glass, stone, bone | No | Yes, where density differs sufficiently from the product |
| Thin stainless in a light product | Often better | Often worse — thin stainless gives weak contrast |
| Metallised film and foil trays | Does not work — the packaging is metal | Works |
| Product effect (wet, salted) | Reduces achievable sensitivity significantly | Unaffected |
| Fill level and missing components | No | Yes |
| Purchase cost | Lower | Typically several times higher |
| Running cost | Low. No special requirements | Higher. Shielding, generator life, trained staff, regulatory obligations |
| Space in the line | Compact | Requires more space and shielding |
How to decide in practice
Choose a metal detector if your documented hazard is metal from your own process — blade fragments, machine parts, needles, sieve wire — and the packaging is not metallised. That covers the large majority of meat, seafood, dairy and bakery production.
Consider X-ray if you have a documented glass or stone hazard, if you pack in foil trays or metallised film and cannot move inspection before sealing, or if you also need to verify fill and component presence.
Consider both if you have both hazards. Many producers run a metal detector late in the line and X-ray on incoming raw material — or the other way round.
A common misconception worth naming: X-ray is not automatically "better". On a thin bag of crisps or a light, dry product, a metal detector is typically more sensitive to small stainless fragments than an X-ray system. Choose on the hazard, not the price tag.
How do you find out for your own product?
By measuring. Send a sample to our test centre and we will run it with test pieces in ferrous, non-ferrous and stainless steel and tell you what can realistically be detected. If the answer is that a metal detector cannot solve your problem, we will say so — that is faster for both of us than a quotation that goes nowhere.
Not sure what can be detected in your specific product? Send us a sample. You get a written test report with false reject rate and probability of detection — free and normally within a week.
Related: Compare the detection systems · Metallised film in bakery and snacks · What the standards require