FIBRE OPTIC DEVICE FOR LINEAR DISPLACEMENT LOGGING Russian patent published in 2009 - IPC G01V1/16 

FIELD: mining; physics.

SUBSTANCE: fibre optic device for linear displacement logging consists of at least one sensor including pressure tight frame, inertia mass with suspension system, magnet damping system, mirror reflecting surface and attachment point of fiber cable, also it consists of fiber cable connecting sensor with base station and base station including module for generating, processing and logging of signals. Also the system of suspension of inertia mass is made in form of non-contact magnet suspension of two pairs of circular magnets; a stabilising core is inserted in a lower part of inertia mass; the mirror reflecting surface is made in form of a narrow cylinder mirror and is located on the surface of inertia mass parallel to the inertia mass displacement axis. As a fibre cable connecting the base station with the sensor there is used a single-core multimode fiber cable; number of sensors is determined from one to ten; notably the sensors are arranged along the single-core multimode cable and are connected with one module for generating, processing and logging of signals of the base station. Duration of an optical pulse which is generated by means of the base station is significantly less, than duration of optic pulse advancing from the base station to the nearest sensor and back; the amount of modules for generating, processing and logging of signals of the base station corresponds to the amount of directions of seismic network on base of single-core multimode fibre optic cables with sensors arranged along them. Also the module for generating, processing and logging of signals of the base station contains a controller for communications with a personal computer, the signals from which are transmitted to a synchronic generator; control pulses exit the latter and enter a current switch and pulse laser; the pulse laser is connected with the single-core multimode fiber cable via the interconnecting optical circuit of transceiving optical pulses; the module further contains an optical receiver logging a signal from the interconnecting optical circuit of transceiving optical pulses; the receiver is connected to an amplifier and to an analog-digital converter; the module also contains a generator of control pulses for the receiver and pulse laser. The attachment point of the fibre cable on the base station and sensors is made with an optical jack.

EFFECT: upgraded process characteristics; simplification of design, such feature as arranging several sensors on one fibre cable, implementation of control system of area perimeter or seismic prospecting at minimal length of fiber cable; reduced labour and material cost.

4 cl, 6 dwg