Educação matemática pela arte
Gusmão, Lucimar Donizete
2013-08-28
Search results
21 records were found.
This paper describes the first demonstration of increasing the dynamic range of Brillouin-based distributed temperature sensor at 1533 nm using Raman amplification provided by a 1450 nm pump source.
The relative accuracy of temperature and strain determination using Brillouin frequency shift and power change in standard single-mode fibre and the frequency shifts of the two Brillouin peaks in large effective area fibre is reported.
A recently proposed method of measuring the two Brillouin frequencies in a multicompositional fiber core for unambiguously resolving temperature and strain in a distributed sensor is compared with the previously established technique of measuring the intensity and frequency of the single Brillouin peak in a standard single-mode fiber.
We report the longest sensing range of a distributed temperature change measurement along an optical sensing fibre with single-ended access. The technique is based on spontaneous Brillouin scattering and microwave heterodyne detection. The Brillouin frequency shift was used to obtain the distributed temperature change at a range of 100 km with a temperature error of less than 8 °C, and a spatial resolution of 50 m.
We report on a novel method for simultaneous distributed measurement of temperature and strain based on spatially resolving both spontaneous Raman and Brillouin backscattered anti-Stokes signals. The magnitude of the intensity of the anti-Stokes Raman signal permits the determination of the temperature. The Brillouin frequency shift is dependent on both the temperature and the strain of the fiber; once the temperature has been determined from the Raman signal, the strain can then be computed from the frequency measurement of the Brillouin signal.
The relative accuracy of temperature and strain determination using Brillouin frequency shift and power change in standard single-mode fibre and the frequency shifts of the two Brillouin peaks in large effective area fibre is reported.
Brillouin intensity and frequency measurements achieved temperature and strain to be unambiguously resolved with resolutions of 3.5°C and 85με at 50km. Frequency only measurements achieved temperature or strain resolution of 1.7°C and 35με at 100km.
We report the longest distributed temperature sensor based on microwave heterodyne detection of the frequency of the anti-Stokes Brillouin signal. At a sensing range of 100km, the temperature accuracy was 8degC, with a spatial resolution of 50m.
Key results: The temperature change measurement at 60km of sensing fibre is reported for the first time. How does the work advance the state-of-the-art?: Measuring temperature change at this long range will help the development of long range high performance temperature distributed optical sensors.
Motivation (problems addressed): Long range temperature sensors above 57km have not been previously realised. Existing applications demand greater range.
We report on a novel method for simultaneous distributed measurement of the temperature and strain in an optical fibre based on spatially resolving the anti-Stokes signals of both the spontaneous Raman and Brillouin backscattered signals.
