Abstract: A sensor array for measuring the deformation of an area caused by a force, comprises a first strip and a second strip arranged in the same plane on the area so as to form a tunnel junction of which at least the first strip is movably arranged on the area so that the gap between the two strips is increased when the area is deformed as a result of the action of the force.

Abstract: A sensor array for measuring the deformation of an area caused by a force, comprises a first strip and a second strip arranged in the same plane on the area so as to form a tunnel junction of which at least the first strip is movably arranged on the area so that the gap between the two strips is increased when the area is deformed as a result of the action of the force.

Abstract: A test device and process for inspecting the integrity of prestressed construction elements. The device comprises a testing head having a magnetization device for generating a magnetic field around the construction element. The testing head is connected to a controller device for controlling the magnetization process and for processing signals corresponding to the magnetic field. The testing head magnetizes the construction element over a predetermined measurement section. The controller switches the magnetization device after the magnetization process is completed and then stores and processes the signals recorded.

Abstract: A gradiometer for measuring magnetic field gradients has two SQUID loops lying in a SQUID loop plane with a flux concentrator lying in a flux concentrator plane parallel to the SQUID loop plane. The flux concentrator body is mirror symmetrical with respect to a plane of symmetry perpendicular to the SQUID plane and the flux concentrator plane along a basis line connecting the centers of the SQUID loops.

Abstract: A method of producing and verifying integrity of a structure in which an elongated ferromagnetic reinforcements are magnetized externally of the structure with a magnetic field strength sufficient to detect magnetization at the structure after the reinforcing is embedded in concrete or another building material. For the evaluation of the integrity of the structure a magnetic field sensor is displaced along a surface of it and the magnetic field from the previously magnetized reinforcement is recorded as a function of displacement of the sensor.