What is the role of a metal detector in preventing physical hazards from entering the food supply chain?

A metal detector plays a crucial role in preventing physical hazards, specifically metal fragments, from entering the food supply chain. Metal fragments can originate from various sources during food processing, including worn or damaged equipment, broken machinery parts, or accidental contamination from tools and utensils. Metal detectors are designed to detect the presence of ferrous (iron-containing), non-ferrous (e.g., aluminum, copper), and stainless steel contaminants in food products. These detectors work by creating an electromagnetic field; when a metal object passes through this field, it disrupts the field, triggering a rejection mechanism that removes the contaminated product from the production line. For example, a metal detector might be placed after a grinding or cutting operation where there is a risk of metal shards entering the product stream. By detecting and removing these metal contaminants, metal detectors prevent consumers from ingesting potentially harmful foreign objects, reducing the risk of injury or illness. Regular testing and calibration of metal detectors are essential to ensure their sensitivity and accuracy in detecting metal fragments of specified sizes and types. The sensitivity is the minimum size of metal fragment that the detector can reliably detect. The rejected product is then investigated to identify the source of the metal contamination and implement corrective actions to prevent future occurrences.