A new technique for interrogating fiber optic sensors with Bragg gratings / Uma nova tecnica para interrogação de sensores a fibra otica com grades de Bragg

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The recent advances in fiber optics and eletronic circuits has led to the development of many sensors based on fiber optics, with a great emphasis on Fiber Bragg Gratings (FGB) sensors. The FGBs sensors are used to quantify severeal measurands, as temperature, pressure, tension, thermodynamics and electrical current, with good accuracy and resolution. In this projec, a novel low cost technique for interrogating a temperature FBG sensor was developed. The FBG sensor is iluminated with a DFB laser which contains a Thermo Electrical Cooler (TEC) and a thermistor. An eletronic analog circuit controlled by a high-performance 100 MIPS 8051CF120 microcontroller drives the TEC with a controlled current, changing the temperature of the DFB laser and, consequently, changing the wavelength in its output. The FBG temperature measurement is implemented with an algorithm stored in the microcontroller flash memory. When the temperature changes in the FBG, the system has to con-tinuosly track the FBG as it moves around the spectrum due to the temperature variations. This novel simple low-cost and good precision technique for making an all eletronic interrogator for measuring temperature with FBGs sensors was develeped. The unique charecteristic of associating the Bragg shifts with thermistor measured values is the main feature of the proposed interrogation scheme

ASSUNTO(S)

eletronica optoeletronics microeletronics optoeletronica eletronics eletronics microeletronica detectores oticos eletronica - instrumentos digitais

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