FIELD: measuring equipment.
SUBSTANCE: invention relates to measuring equipment using optical fiber, to fiber-optic security detectors. A fence with a means of detecting a tunnel with a linear part of a security fiber-optic detector is formed by an obstacle stretched between pillars installed on foundations, between which a detector sensor element is stretched in the ground at a depth of physical impact, using combined interferometers containing a stationary piece with a transceiver connected to the linear part consisting of a branched optical circuit based on splitters and a fiber-optic cable connecting the transceiver device and sensitive elements, generating reflection signals, in which the segments of the optical fiber of the cable are sensitive elements of interferometers, in which a phase shift of the probing pulse is created in accordance with the physical effect, one closed circuit is the Mach-Zender interferometer, and the other closed circuit is the Sagnac interferometer.
EFFECT: increase in the accuracy of determining the location of the impact on the sensitive element, the implementation of its concept.
10 cl, 12 dwg
