Metal Detector Introduction

A metal detector is a metal detection device consisting of a metal detector and an automatic rejection mechanism, with the detector being the core component. The system can use the alarm signal to activate automatic rejection mechanisms, thereby removing metal contaminants from the production line.
The detector contains three sets of coils: a central transmitting coil and two corresponding receiving coils. An oscillator connected to the central transmitting coil generates a high-frequency variable magnetic field. In the idle state, the induced voltages in the two receiving coils cancel each other out, achieving equilibrium, unless the magnetic field is disturbed.
Once metal contaminants enter the magnetic field, this equilibrium is disrupted, and the induced voltages in the two receiving coils cannot cancel each other out. The remaining induced voltages are amplified and processed by the control system, generating an alarm signal (metal contaminants detected). The system can use this alarm signal to activate automatic rejection mechanisms, thereby removing metal contaminants from the production line.
The components used in metal detectors have evolved from vacuum tubes and transistors to integrated circuits, expanding their application to nearly every field, playing a vital role in industrial production and personal safety.