The basics of a LIOS sensing system

A walk-through of the components in a LIOS sensing system

Basically, a LIOS sensing system – be it a DTS or DAS system – consists of a controller (frequency generator, laser source, optical module, HF mixer, receiver, and microprocessor unit) and an optical fiber as a line-shaped temperature sensor.

The power output of the laser runs through the sinus-shaped frequency starting from a starting frequency in the kilohertz range through the ending frequency in the high megahertz range within a measurement time interval with the help of the High Frequency (HF) modulator. The resulting frequency shift is a direct measurement of the local resolution of the reflectometer. The frequency-modulated laser light is connected to the fiber optic-sensor via the optical module.

The continuously back-scattered Raman light is spectrally filtered in the optical module and converted into electrical signals by means of photodetectors. Then the measurement signals are amplified and mixed in the Low-Frequency spectral range (LF range). The Fourier transformation of the averaged LF signals results in the two Raman backscatter curves. The amplitudes of these backscatter curves are proportional to the intensity of the Raman scattering of the viewed location.

Mean Time Between Failures of 40+ years

Reliability is critical when it comes to DTS systems. With 5,000 DTS systems in operation, we have calculated a remarkable MTBF of 40+ years.

Made from Telcordia rated components, passive cooling, and no moving parts, our DTS systems are basically maintenance-free. The self-diagnosing features free you from worrying and allow you to focus on other important tasks.

 

 

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