Abstract: A security screening installation system for use in a controlled environment is described. In an embodiment, a passive detector apparatus does not produce a magnetic field for detection and relies on detecting changes in the local magnetic field. The apparatus is: (i) battery powered; (ii) light enough to be hand carried by hand and set up by one person; (iii) comprises a single elongate housing; and (iv) operable between a packed state inside a protective case and a ready to use state outside of the protective case. The housing supports at least two magnetic sensors that define a gradiometer which is arranged to produce a signal indicative of an ambient magnetic field or gradient over a zone of sensitivity which extends away from the housing, wherein a size of the zone is large enough to contain a whole body of a person.

Abstract: A method of detecting contraband about a person using a portable detector apparatus having an elongate housing that supports at least one magnetic sensor, which is arranged to produce a signal indicative of an ambient magnetic field or gradient over a zone of sensitivity which extends away from the housing, the size of the zone large enough to contain the whole body of the person, and a signal processing circuit that receives as an input the signal from the magnetic sensor and which, in response to a change in the signal, produces an alert signal includes setting up the portable detector apparatus in a chosen location, causing the person to pass alongside the housing from outside of the zone of sensitivity into the zone of sensitivity, and monitoring for the issue of an alert by the device which is indicative of the possible presence of contraband.

Abstract: A method of detecting contraband about a person using a portable detector apparatus having an elongate housing that supports at least one magnetic sensor, which is arranged to produce a signal indicative of an ambient magnetic field or gradient over a zone of sensitivity which extends away from the housing, the size of the zone large enough to contain the whole body of the person, and a signal processing circuit that receives as an input the signal from the magnetic sensor and which, in response to a change in the signal, produces an alert signal includes setting up the portable detector apparatus in a chosen location, causing the person to pass alongside the housing from outside of the zone of sensitivity into the zone of sensitivity, and monitoring for the issue of an alert by the device which is indicative of the possible presence of contraband.