FIELD: electrical engineering.
SUBSTANCE: fence with a tool for detecting a tunnel with a linear part of the fibre-optic security detector constitutes a fence formed by an obstacle stretched between posts installed on foundations, wherein the sensing element of the linear part of the fibre-optic security detector is stretched between said posts in the soil at the depth of the maximum probability of physical impact. A hardware delay line is included in the optical circuit of the fibre-optic security detector, made by connecting the required length of backup cores of the fibre-optic cable into an optical circuit.
EFFECT: increase in the operational reliability of the detector, in particular, due to the exclusion of weakly protected compensation coils necessary to compensate for the length of the fibres of the sensing element from the composition thereof.
10 cl, 12 dwg
