Buried utility locator systems, including a locator including an integrated marker device excitation transmitter for generating and sending a marker device excitation signal to one or more marker devices, are disclosed.

Techniques for operating a tool include moving a tool in a magnetized tubular member that generates a stationary magnetic field. The tool includes a housing that defines an interior volume, a first magnetic field sensor positioned on or within the housing at a first location, and a second magnetic field sensor positioned on or within the housing at a second location apart from the first location by a separation distance. The techniques further include detecting a first magnetic field amplitude distribution sensed by the first magnetic field sensor started at a first time instant; detecting a second magnetic field amplitude distribution sensed by the second magnetic field sensor started at a second time instant; determining a time difference between the first and second time instants based on the identified magnetic field amplitudes; and determining a speed of the tool based on the separation distance and the time difference.

A hyperthermia implant 20 for hyperthermia treatment of tissue 30 of a human or animal body. The implant comprises at least one piece of a large Barkhausen jump material (LBJ) and a magnetic field may be applied to the implant to heat the surrounding tissue. The implant may also be deployed to mark a tissue site in the body for subsequent surgery, thereby providing a combined system for locating an implant and treating the surrounding area. The system includes a handheld probe 14 to excite the implant below the switching field for bistable switching causing a harmonic response to be generated in a sub-bistable mode that allows the implant to be detected and localised.

A magnetic coupler for inducing a signal on a buried utility wire. The coupler has two elongated jaws, each extending along a separate longitudinal axis. The jaws are attached at a hinge. The jaws may be placed about an exposed portion of the utility wire. A signal generate provides a signal which is emitted from a transmitter in each of the jaws. The signals emitted from each jaw are antiphase to one another, such that they are additive to a utility wire disposed between the jaws but out of phase with respect to any utility not between the jaws. The signal is thus induced on the utility wire and can be detected as emitted from its below ground length by a conventional locator.

Provided is an event detection method comprising: obtaining an event occurrence position based on a magnetic field detected by a magnetic sensor; selecting a detection axis for event detection based on the event occurrence position; calculating a trigger threshold value according to the event occurrence position on the detection axis; and obtaining a trigger signal indicating that the magnetic field detected by the magnetic sensor and the trigger threshold value meet a predefined condition.

A magnetic response distribution visualization device includes: an induction circuit that induces a magnetic field component from outside a moving object; a sensor that senses a strength and a phase of the magnetic field at a plurality of points in times outside the moving object; and an information processing circuit that, based on a sensing result of the strength and the phase, a moving speed of the moving object, and a fundamental equation for magnetic fields, calculates a strength and a phase of the magnetic field at a vicinal position closer to the moving object than the sensor, and generates, based on a calculation result of the strength and the phase, a magnetic response distribution image for security inspection that shows a distribution of a response of the moving object to the magnetic field component induced by the induction circuit.

Magnetic field cancelling audio systems and associated devices are disclosed. In one embodiment, an audio system with two electromagnetic audio drivers positioned and electrically connected to reduce emitted magnetic fields over a range of predefined frequencies.

Access control for an autonomous vehicle through a door in a doorway. A magnet is attached to the autonomous vehicle and a magnetometer is located some distance from the doorway. The magnetometer outputs a magnetometer signal in response to detecting the magnet, which causes the transmitter to transmit a detection signal. A doorway device is fixed about the doorway, and includes a receiver, and a locking mechanism with a locking pin. The doorway device retracts the pin to unlock the door for a predetermined period of time in response to receipt of the detection signal, and extents the pin to lock the door after the predetermined period of time ends.

There is provided a method of installing a magnetic proximity sensor including positioning the magnetic field sensor in a desired location and positioning a magnet in a desired location relative to the magnetic field sensor, with an indicator of the sensor continuing to be turned on during the predetermined period of time when the magnetic field generated by the magnet is sensed by the magnetic field sensor, and being turned off during the predetermined period of time when the magnetic field generated by the magnet is not sensed by the magnetic field sensor. The indicator light thus assists in determining proper relative positioning of the magnet and the magnetic field sensor. If after the predetermined period of time more time is needed to install the magnetic proximity sensor, the method includes initiates another predetermined period of time by removing and replacing a lid of the magnetic proximity sensor.

A method for operating a sensor device for detecting an object, having a first surroundings sensor and a second surroundings sensor for detecting a surroundings of the sensor device, including detecting a surroundings of the sensor device using the first surroundings sensor to ascertain first surroundings data, the second surroundings sensor being deactivated; ascertaining whether the first surroundings data are sufficient to be able to conclude with a predetermined probability whether an object is located in the surroundings; if the first surroundings data are sufficient, ascertaining whether an object is located in the surroundings, based on the first surroundings data; if the first surroundings data are not sufficient, activating the deactivated second surroundings sensor; detecting the surroundings of the sensor device using the second surroundings sensor to ascertain second surroundings data; ascertaining whether an object is located in the surroundings, based on the second surroundings data.