Abstract: Optical fibre based measurement system having a system for generating radiation (Z) with monotonically tuneable wavelength during sweep periods, an optical path (T) and a detector (D) connected to the system for generating radiation (Z) via the optical path (T). The optical path (T) comprises the interferometer (I) comprising the multi-port element (EW) and the attached measuring optical fibre (F) sensitive to at least two environmental parameters, the mode excitation system (P) adapted for excitation in the measuring optical fibre (F) of at least the measuring mode (Mnl) with the first effective refractive index and the measuring mode (Mn2) with the second effective refractive index, having different sensitivity to these two parameters. The measurement system comprises the processing unit (UP) to which the detector (D) is connected via the analogue-to-digital converter (ADC), and the processing unit (UP) is adapted to generate the control signal for the system for generating radiation (Z).

Abstract: A temperature monitoring device containing a control system adapted to generate substantially periodic control waveforms applied to the control input of the light source with tunable wavelength connected to an optical fiber interferometer, in which a measuring optical fiber is connected in one its arms, and the interferometer output is connected to a detector whose output is connected to a signal processing module adapted to identify temperature changes in the optical fiber length function, in accordance with the invention, characterized in that the light source coherence length is longer than 0.5 m, and the period of the periodic waveform is shorter than or equal to 20 s, the difference between the minimum and maximum wavelength is higher than 3 ?m, and the optical fiber is adapted to its placement near exoenergetic devices in a vehicle, during its operation.