Routine testing of metal detection systems is an essential component of food safety protocols, ensuring that manufacturers meet both regulatory and retailer standards while minimising the risk of contamination. Mettler-Toledo Safeline highlights that metal detectors must be regularly validated, verified and monitored to remain effective across changing production conditions.

Validation confirms a detector’s suitability at installation, while periodic verification—typically every 6 to 12 months—checks ongoing sensitivity and performance. Routine performance monitoring during production identifies any changes in sensitivity due to product variations, machine adjustments or wear and tear.

Testing approaches vary by application. Conveyor-based systems require checks across the entire product path to confirm detection and rejection reliability. Free-fall and pipeline systems demand strategic placement of test pieces to ensure contaminants are identified regardless of product flow dynamics. Tests should mirror actual production conditions, including worst-case scenarios.

Retailers often impose additional protocols such as consecutive testing, memory tests and large metal checks to confirm consistent system performance and minimise false rejects. These standards also define when tests must occur—typically during shift changes, after maintenance, or product switches.

New technologies are helping streamline this process. Automated Test Systems (ATS), Reduced Test Mode (RT Mode), and HMI emulation allow for safer, more consistent, and less labour-intensive testing. Digital tools such as electronic recordkeeping further enhance traceability and compliance.

Ultimately, a robust testing strategy not only safeguards consumers but also helps manufacturers avoid costly recalls and maintain trust across the supply chain.