(under subclass 244) Subject matter wherein the apparatus to
sense a magnetic field includes a ferromagnetic core having an alternating magnetic flux passing through the core, the magnetic field tested being concurrently passed through the core with the alternating flux and an electrical coil to sense the change in the magnetic flux caused by the magnetic field in the core, the apparatus to indicate being responsive to the electrical coil sensing the magnetic field change in the core.
SEE OR SEARCH THIS CLASS, SUBCLASS:
228, for the magnetic testing of material.
236+, particularly, which use coil-type magnetic field sensors.
SEE OR SEARCH CLASS
33, Geometrical Instruments,
361, for flux gate sensors used in magnetic field responsive instruments indicating the direction of force traversing natural media. 318, Electricity: Motive Power Systems,
47, for magnetic field sensors that control an electric motor servo-system.
340, Communications: Electrical,
870.33, for continuously variable indicating apparatus having an inductor of the flux gate type.
341, Coded Data Generation or Conversion,
20+, and 173+ for a code transmitter having a flux gate magnetic sensor.
360, Dynamic Magnetic Information Storage or Retrieval,
111, for flux gate magnetic sensing heads to sense or record information.
361, Electricity: Electrical Systems and Devices,
93.6, for abnormal current condition protection including transformer sensor, and subclasses 143+ for drive circuits for flux gate magnetic sensing devices which create the alternating flux for the sensing devices.
