A detector (10) for detecting electrically conductive material is provided. The detector (10) comprises at least one transmitter (11) having a transmitter coil (12) and a supply source (13), a receiver (14) having a receiver coil (15), and an evaluation unit (16), wherein the transmitter coil (12) is connected to the supply source (13), the supply source (13) is configured to provide an alternating voltage or an alternating current when in use, the receiver (14) is designed as a resonant-circuit-free receiver, the receiver (14) is connected to the evaluation unit (16), and the evaluation unit (16) is configured to detect a signal induced in the receiver coil (15).

A railroad crossing control system (100) includes a constant warning time device (40) with a control unit (50) configured to produce multiple signals, and a wheel sensing system (120) comprising at least one sensor (122) connected to a rail (20a, 20b) of a railroad track (20) at a predetermined position (P), wherein the wheel sensing system (120) detects a presence of railroad vehicle travelling on the railroad track (20) such that the at least one sensor (122) detects wheels of the railroad vehicle using electromagnetic fields, wherein the wheel sensing system (120) provides speed values of the railroad vehicle to the constant warning time device (40), and wherein the constant warning time device (40) produces a constant warning time signal for controlling a railroad crossing warning device in response to receiving the speed values of the wheel sensing system (120).

A railroad crossing control system (100) includes a constant warning time device (40) with a control unit (50) configured to produce multiple signals, and a wheel sensing system (120) comprising at least one sensor (122) connected to a rail (20a, 20b) of a railroad track (20) at a predetermined position (P), wherein the wheel sensing system (120) detects a presence of railroad vehicle travelling on the railroad track (20) such that the at least one sensor (122) detects wheels of the railroad vehicle using electromagnetic fields, wherein the wheel sensing system (120) provides speed values of the railroad vehicle to the constant warning time device (40), and wherein the constant warning time device (40) produces a constant warning time signal for controlling a railroad crossing warning device in response to receiving the speed values of the wheel sensing system (120).

Magnetic field measurement by a set of magnetometers which are linked to a same moveable support and which have different orientations of eigendirections with respect to this support A processor determines, during a measurement in a given position and orientation of the support and of the set of magnetometers, for each magnetometer, of the orientation deviation between the eigendirections of the magnetometer and a candidate magnetic field, the magnetometer for which this deviation is minimal, the magnetic field measured by this sensor being selected as the magnetic field measured by the set of magnetometers. The magnetometers are distributed in space in order to cover a maximum of different orientations.

A proximity sensor comprises a reference inductor, a first set of sensor inductors, a first set of comparators, each comparator of the first set of comparators corresponding to one of the sensor inductors of the first set of sensor inductors, and an alternating current voltage source to output a sinusoidal voltage to the reference inductor and each of the sensor inductors. Each comparator of the first set of comparators receives a voltage across the reference inductor as a reference voltage and each comparator of the first set of comparators receives a voltage across a corresponding sensor inductor as an input voltage.

A proximity sensor comprises a reference inductor, a first set of sensor inductors, a first set of comparators, each comparator of the first set of comparators corresponding to one of the sensor inductors of the first set of sensor inductors, and an alternating current voltage source to output a sinusoidal voltage to the reference inductor and each of the sensor inductors. Each comparator of the first set of comparators receives a voltage across the reference inductor as a reference voltage and each comparator of the first set of comparators receives a voltage across a corresponding sensor inductor as an input voltage.

The present invention relates to a dual-technology detecting system, comprising: -an archway, -a metal detector housed in a first segment of the side panels, -a millimetre-wave body scanner housed in a second segment of the side panels, said body scanner comprising at least one antenna configured to emit radiant energy, wherein, within the first segment, the internal faces of the side panels are separated by a distance at least equal to 800 mm and smaller than or equal to 900 mm, and within the second segment, a maximum distance between the internal faces of the side panels is larger than or equal to 1000 mm and smaller than or equal to 1200 mm.

Techniques are described for monitoring and controlling fall protection equipment. For example, the techniques of this disclosure may be used to monitor the connection status of fall protection equipment, e.g., whether or not the fall protection equipment is connected to a support structure. The techniques described in the disclosure may determine whether the fall protection equipment is connected to a support structure based on changes in a resonant frequency of an electronic circuit of an inductive sensor within the fall protection equipment. The inductive sensor may be formed from sets of one or more coils, where a first set of one or more coils and a second set of one or more coils are wound in opposite directions.

A floor-mounted security device able to test personnel for metal material carried in or at the bottom of their footwear includes an induction module, a pressure sensing module, and an automatic alarm module. The pressure sensing module senses weight and pressure of a person standing, and outputs a trigger signal to the induction module to trigger operation of the induction module. The induction module can detect the presence of a metal mass by the change in a magnetic field, and output a control signal accordingly. The automatic alarm module outputs an alarm when prompted by the control signal.

A floor-mounted security device able to test personnel for metal material carried in or at the bottom of their footwear includes an induction module, a pressure sensing module, and an automatic alarm module. The pressure sensing module senses weight and pressure of a person standing, and outputs a trigger signal to the induction module to trigger operation of the induction module. The induction module can detect the presence of a metal mass by the change in a magnetic field, and output a control signal accordingly. The automatic alarm module outputs an alarm when prompted by the control signal.