Abstract: A building rests on the soil. Vertical elongation detectors are placed at the base of pillars above bearing points of the building on the soil, in particular at the corners of the building. Variations in the measurements of vertical elongation of the pillars indicate a variation in the ability of the soil to support the building. In particular, the partial or total unloading of a pillar gives rise to suspicion of a compaction of the soil under the pillar. The present method is usable for very early detection of risk situations that might eventually compromise the safety of a structure.

Abstract: In the field of monitoring the aging of parts subjected to a rotary movement and, more precisely, of monitoring the deformation to which a peripheral surface of a rotating part is possibly subject, an improved method is provided. The method includes: a step of emitting a light signal at a first end of an optical fiber at least one section of which runs between two points of the surface of the part; a step of measuring a characteristic of the light signal received at a second end of the optical fiber, the characteristic varying as a function of the length of the optical fiber between its ends; and a step of comparing the characteristic of the light signal to a reference signal.

Abstract: A monitoring device is provided that is used for the monitoring of an area of building or land, including an optical strand used as a sensor, one optical source for emitting an optical emission signal transmitted in the optical strand, and one optical analogue detector for detecting an intensity of an optical return signal corresponding to the optical emission signal returning from the optical strand. The monitoring device is arranged as a compact unit and includes a controller for alternately activating and deactivating the emission of the optical source so that a ratio between the non-emission duration and the emission duration is greater than 5000. A monitoring system is also provided including such a monitoring device, and a monitoring method carried out in the monitoring device.

Abstract: In the field of monitoring the aging of parts subjected to a rotary movement and, more precisely, of monitoring the deformation to which a peripheral surface of a rotating part is possibly subject, an improved method is provided. The method includes: a step of emitting a light signal at a first end of an optical fibre at least one section of which runs between two points of the surface of the part; a step of measuring a characteristic of the light signal received at a second end of the optical fibre, the characteristic varying as a function of the length of the optical fibre between its ends; and a step of comparing the characteristic of the light signal to a reference signal.

Abstract: A monitoring device is provided that is used for the monitoring of an area of building or land, including an optical strand used as a sensor, one optical source for emitting an optical emission signal transmitted in the optical strand, and one optical analogue detector for detecting an intensity of an optical return signal corresponding to the optical emission signal returning from the optical strand. The monitoring device is arranged as a compact unit and includes a controller for alternately activating and deactivating the emission of the optical source so that a ratio between the non-emission duration and the emission duration is greater than 5000. A monitoring system is also provided including such a monitoring device, and a monitoring method carried out in the monitoring device.

Abstract: A bridge comprises a floor, one end of which embodying a first bearing line rests on a shoulder of an abutment by means of two end bearings. Detectors of vertical dimensional variation are connected to the bearings. When a vehicle crosses the end of the floor, the sudden variation in vertical dimension experienced by the bearings when each axle of the vehicle reaches the end of the floor is detected. These sudden variations are analyzed in order to develop a measurement of the weight transmitted to the ground by each of the axles. The sum of these weights provides a measurement of the total weight of the vehicle. When a pre-determined limit is exceeded, alarms and/or actions are triggered. The invention is useful for simple, economic and systematic checking of the observance of the maximum weights authorized for vehicles crossing a bridge or more generally following a determined route.

Abstract: An apparatus such as a television receiver set, an encrypted programme decoder, etc., has, in particular on its remote control unit, a key (44) with multiple mobility for triggering repetitive reproduction, slightly delayed, of a most recent completed fragment of the sequence currently received live. The multiple mobility of the key (44) enables to parameterize the delayed reproduction for forward, rewind, slow motion, fast motion, picture-by-picture reproduction, the starting point of the delayed reproduction in the recorded fragment. The invention enables to acquire more accurate knowledge of details selected from a sequence occurring normally in real time.

Abstract: The invention concerns a method whereby a succession of elements (1) designed to be placed against the structure to be monitored by pressing the baseplate (4) of each element against a surface of the structure. The elements (1) are linked by articulations (2) and the mutual angular deflection of the elements (1) is read by sensing devices (19). The signal from the sensors is processed by a processing unit (29). The invention is useful for very simple installation of an essentially prefabricated and pre-cabled detector.

Abstract: To detect by means of a long-baseline system the global bending strain of a structure (1), i.e. by detecting the accumulated local bending strains over a distance of at least two meters, detection lines (8, 11), preferably optical fiber lines, which indicate the extent of their elongation by an increased attenuation of the light pulses which run through them, are used. To detect the direction and the extent of the flexure of the structure (1), the latter is closely associated with a model comprising a matrix (13) which follows the flexural bending strains of the structure (1), and at least one, preferably two detection lines (8, 11) suitably located in the matrix cross-section so that their elongation variations and/or the differences between their respective elongation variations are indicative of the flexure of the model, which gives indications on the flexure of the structure (1).