When the laser pulse generated in the DTS relay module is incident on the optical fiber of the FOS linear sensor, scattering and absorption of light occur due to the glass gratings (SiO2) in the optical fiber. In the scattered light due to this, Raman scattering light is generated due to the interaction with the transverse mode among the lattice thermal vibrations of the constituent material, and the characteristic change according to the temperature occurs, so that the TDS relay can measure the accurate temperature. In addition, after the laser pulse is incident on the optical sensor linear detector, the position of the fire is measured by calculating the return time of the scattered light and accurately checking the reflected spot.

Unlike conventional warm-tempered linear detectors, which operate only at specified temperatures, FOS linear detectors can freely set zone lengths and alarm thresholds on SRF receivers.

In addition, as an analog detector, it is suitable for the installation site by the fixed-temperature type, the differential type, or the complementary detection method which is a mixture of the two types. Stainless steel tubes with optical fiber are durable in explosion-proof, cryogenic, and high-humidity areas and do not corrode chemical substances such as SO2, NO2, and CO contained in the vehicle exhaust gas. FOS linear detectors are available for up to 30 years and have a semi-permanent life.

Specifications