Image Number 2 for United States Patent #6639403.
A method and system for sensing magnetic fields using an AC current carrying wire which vibrates or moves in the presence of a magnetic field. The system uses the wire movement to determine one or more characteristics of the field. The wire is connected at a first and second location to the base with an portion between the connection locations having an apex spaced apart from the base. The monitoring system detects movement of the wire at the portion while an electrical current having the same frequency as the mechanical resonant frequency of the wire is sent through the wire and a magnetic field surrounds the portion. The reporting system determines one or more characteristics of the magnetic field based upon the detected movements.