Found in many older buildings that have not been fully upgraded. The current from an electrical circuit or device that flows to ground, usually as a result of imperfect insulation. The force field produced by an electric current. The measurement of the strength and direction of a magnetic field in a given area. A form of non-ionizing radiation.
Radar is a form of microwave radiation.
These are generally used as services or secondary wiring. It is a name for a general group of alloys which allow magnetic lines of force to concentrate within them, thus freeing the space outside the material of high permeability of those force lines which would otherwise constitute a magnetic field. This metal is useful for shielding purposes and is produced in thicknesses down to foil gauge. Detected by either a gauss meter or a clamp-on ammeter clamped around the entire circuit. The magnetic field produced by net-current acts the same way as a field from the same current traveling in a single conductor.