How Do Metal Detectors Work In Food Industry

Basically there are several types of metal detectors that operate with different detection methods. In the food industry, metal detectors usually apply the transmitter-receiver method (see graphic). Such metal detectors are equipped with a transmitter coil and two receiver coils.The electronic unit in the metal detector analyses this signal, evaluates it and signals a metal contamination.
            
Such metal detectors are equipped with a transmitter coil and two receiver coils. The transmitter coil generates a constant electromagnetic field. When a metal particle passes the detector it interferes with the electromagnetic field, causing a signal to be detected by the receiver coils. The electronic unit in the metal detector analyses this signal, evaluates it and signals a metal contamination. As a rule metal detectors in the  food industry are equipped with automatic reject units that directly separate the contaminated product from the production line.