Thermal Evaluation of Fiber Bragg Gratings at Extreme Temperatures

Juergens, Jeffrey R.; Adamovsky, Grigory; Bhatt, Ramesh S.; Morscher, Gregory N.; Floyd, Bertram

doi:10.2514/6.2005-1214

Cited by 9 publications

(7 citation statements)

References 7 publications

(12 reference statements)

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“…The long-term wavelength stability of RFBGs at high temperature was presented for the first time in 2005 [ 47 ]. During the heating-up period the original FBGs dissipated at ~880 °C and the respective RFBGs started to emerge at ~913 °C.…”

Section: Literature Reviewmentioning

confidence: 99%

“…After the start of the regeneration process, the Bragg wavelength of the gratings experienced a drift toward longer wavelength (red drift) while the reflectivity of the regenerated gratings increased. By the time the temperature reached 1000 °C, the RFBG reflectivity increased to a maximum value corresponding to ~20 % of the initial reflectivity of the seed grating and then decreased asymptotically to reach a stable value corresponding to ~7% of the initial reflectivity after ~5 h. The gratings were further tested at 1000 °C for ~400 h and the Bragg wavelength was monitored (see Figure 1 ) [ 47 ].…”

Section: Literature Reviewmentioning

confidence: 99%

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Fiber Bragg Grating Wavelength Drift in Long-Term High Temperature Annealing

Grobnic

Hnatovsky

Dedyulin

et al. 2021

Sensors

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High-temperature-resistant fiber Bragg gratings (FBGs) are the main competitors to thermocouples as sensors in applications for high temperature environments defined as being in the 600–1200°C temperature range. Due to their small size, capacity to be multiplexed into high density distributed sensor arrays and survivability in extreme ambient temperatures, they could provide the essential sensing support that is needed in high temperature processes. While capable of providing reliable sensing information in the short term, their long-term functionality is affected by the drift of the characteristic Bragg wavelength or resonance that is used to derive the temperature. A number of physical processes have been proposed as the cause of the high temperature wavelength drift but there is yet no credible description of this process. In this paper we review the literature related to the long-term wavelength drift of FBGs at high temperature and provide our recent results of more than 4000 h of high temperature testing in the 900 –1000°C range. We identify the major components of the high temperature wavelength drift and we propose mechanisms that could be causing them.

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Section: Literature Reviewmentioning

confidence: 99%

Section: Literature Reviewmentioning

confidence: 99%

Fiber Bragg Grating Wavelength Drift in Long-Term High Temperature Annealing

Grobnic

Hnatovsky

Dedyulin

et al. 2021

Sensors

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“…The experimental data is represented with dots. As expected, the SNR exhibits a gradual decrease over time [25], [27], [28], [29], [30]. The thermal decay of the index modulation related to this process can usually be described with an exponential decay (first order Arrhenius) function.…”

Section: A Snr Evaluation In Reactor Environmentmentioning

confidence: 94%

Signal-to-Noise Ratio Evaluation of Fibre Bragg Gratings for Dynamic Strain Sensing at Elevated Temperatures in a Liquid Metal Environment

Pauw¹,

Lamberti

Rezayat

et al. 2015

J. Lightwave Technol.

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Vibration measurements of the fuel assembly of a nuclear reactor are a very useful tool to determine the health and lifetime of the reactor core. The importance of these measurements is exacerbated in the new generation of heavy liquid metal reactors, where the fuel assembly is exposed to a corrosive molten metal coolant at 300 • C and where the space between the individual fuel pins is limited to a few millimeters. In this paper we consider fibre Bragg gratings as potential candidates for carrying out fuel pin vibration measurements in such an environment. We describe a dedicated method to integrate fibre Bragg gratings in a fuel pin and we subject this pin to conditions close to those encountered in a real heavy liquid metal reactor. More specifically, we report on the performance of draw tower gratings used as a vibration sensor when the fuel pins are immersed in heavy liquid metal at 300 • C for up to 700 hours. The performance evaluation is based on monitoring the signalto-noise ratio of the grating's spectral response as a function of time. We show that accurate detection of the Bragg peak becomes very challenging after 400 hours of exposure. Additionally, we succeed to extend the useful lifetime with a factor of two by using an appropriate integration of the fiber in the fuel pin and by using an alternate peak detection algorithm.

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“…A review of the literature reveals an abundance of research and development in a laboratory environment of sensors for harsh environments [8][9][10][11][12][13][14][15][16][17]. Much of this research is focused on exposure of the sensor to high temperature in a laboratory furnace, and on rare occasions elevated cyclic testing.…”

Section: Proposed Approach For Accelerated Sensor Validationmentioning

confidence: 99%

“…Advanced high temperature sensors and instrumentation for potential aircraft gas turbine propulsion health monitoring has been explored through significant research and development in the laboratory in the past two decades [8][9][10][11][12][13][14][15][16][17]. Advanced high temperature sensors and instrumentation for potential aircraft gas turbine propulsion health monitoring has been explored through significant research and development in the laboratory in the past two decades [8][9][10][11][12][13][14][15][16][17].…”

mentioning

confidence: 99%

Opportunities and Challenges in Nde and Health Monitoring of Turbine Engine Components

Mazdiyasni¹

2008

AIP Conference Proceedings

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Articles you may be interested in NDE measurements for understanding of performance: A few case studies on engineering components, human health and cultural heritage AIP Conf.Development of NDE to monitor bond degradation in aircraft honeycomb components AIP Conf.Nondestructive evaluation of creep damage and life prediction of Ni-base superalloy used in advanced gas turbine blades by electrochemical technique AIP Conf.ABSTRACT. Advanced high temperature sensors and instrumentation for potential aircraft gas turbine propulsion health monitoring has been explored through significant research and development in the laboratory in the past two decades [8][9][10][11][12][13][14][15][16][17]. With continued emphasis on safety, improving engine life cycle cost and fuel efficiency, and increasing durability and life, there is strong impetus to move these technologies out of the laboratory and onto the engines. The objective of this paper is to provide a perspective of the opportunities and challenges in implementing advanced nondestructive evaluation (NDE) and health monitoring techniques on aircraft gas turbine engine components, and to propose an approach for accelerating implementation to meet Air Force objectives.

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Thermal Evaluation of Fiber Bragg Gratings at Extreme Temperatures

Cited by 9 publications

References 7 publications

Fiber Bragg Grating Wavelength Drift in Long-Term High Temperature Annealing

Fiber Bragg Grating Wavelength Drift in Long-Term High Temperature Annealing

Signal-to-Noise Ratio Evaluation of Fibre Bragg Gratings for Dynamic Strain Sensing at Elevated Temperatures in a Liquid Metal Environment

Opportunities and Challenges in Nde and Health Monitoring of Turbine Engine Components

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