The Basic Principles

Most modern metal detectors, operate on the balanced coil, full loop system.

Three coils are wrapped around the aperture through which the product passes. In the centre of the enclosure is the transmitter coil that broadcasts a radio frequency signal and generates an

Electro-Magnetic field.

Equally space on either side of the transmitter coil are two receivers coils  (Figures 1 & 2)

The field is generally trapped inside the shielded enclosure of the detector but some file escapes from          the aperture on both sides of the detector.  Anything that enters in this field that is either Magnetic, or Electrically Conductive will cause a disturbance in the field strength around it.  All metals have either one     or both of these characteristics and will be detectable if the size of the signal is large enough.

The signal from the receiving coils are connected in opposition to each other and therefore when no disturbance is occurring there will be a net signal of zero across the coils - they are balanced. This forms   the electrical equivalent of a balanced weigh scale.

As metal passes through the detector the balance will be offset and the contaminant enters the aperture   and again as it leaves on the exit side. This disturbance is amplified and analyzed by the control    electronics and detection will occur if the sensitivity threshold has been exceeded.

But what is the recommended usage? What are the best practices for installation? What  are the latest features? Which type of metal detector is right for your application?

Regal has the answer to this and many more in depth questions regarding metal detection technology,      so feel free to call us any time you like at (800) 378-1226.