The new quasi-distributed frequency-output fiber-optic recirculating sensors for high-voltage measurements and
perimeter security system have been proposed. Fiber-optic sensor was constructed as a closed optoelectronic contour
formed by a source of radiation, an optical fiber delay line, spectral reflective elements, photoreceiver and regeneration
block. The sensitive element of this device was the optical fiber. The change of recirculation frequency or period of the
contour carried out identification of measured parameters with high accuracy. Sensitivity of these sensors was estimated.
Temperature dependence of measurement accuracy was investigated.