scholarly journals Simultaneous Measurement of Temperature and Mechanical Strain Using a Fiber Bragg Grating Sensor

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4223
Author(s):  
Shiuh-Chuan Her ◽  
Wei-Nan Lin
Keyword(s):  
Theoretical Prediction ◽  
Fiber Bragg Grating ◽  
Mechanical Strain ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Physical Parameters ◽  
Bragg Wavelength ◽  
Fbg Sensor ◽  
Host Structure ◽  
As Stress

Based on the shift of the Bragg wavelength, fiber Bragg grating (FBG) sensors have been employed to measure a variety of physical parameters such as stress, strain, displacement, temperature, vibration and pressure. In this work, a simple and easy way to be implemented FBG sensing methodology was proposed to measure the temperature and strain simultaneously. Half of the FBG was bonded on the host structure, while the other half of the FBG was left free. The host structure was an aluminum test specimen with dimensions of 20 × 3.8 × 0.5 cm3. As the host structure subjected to mechanical and thermal loadings, the Bragg wavelengths reflected from the bonded and unbonded FBGs are different. Theoretical predictions of the Bragg wavelength shifts of the bonded and unbonded FBGs were presented. Utilizing the Bragg wavelength shift of unbonded FBG, the temperature can be determined and is independent of mechanical strain. The Bragg wavelength shift of the bonded FBG allows the determination of the mechanical strain. The temperature measured by FBG sensor was compared with the result from a thermocouple, while the mechanical strain was validated with the theoretical prediction. Good agreement between the experimental measurement and theoretical prediction demonstrates that temperature-strain discrimination can be realized using the proposed method with one single FBG sensor.

Application of Fiber Bragg Grating Sensor coated with Polyaniline as an optical Sensor for chloroform detection

2017 ◽  
Vol 25 (7) ◽  
pp. 555-562
Author(s):  
Irma Zulayka Mohamad Ahad ◽  
Sulaiman Wadi Harun ◽  
Seng neon Gan ◽  
Sook Wai Phang
Keyword(s):  
Thin Film ◽  
Fiber Bragg Grating ◽  
Optical Sensor ◽  
Fast Response ◽  
Chemical Oxidation ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Peak Ratio ◽  
Bragg Wavelength ◽  
Fbg Sensor

Fiber Bragg Grating (FBG) sensor coated with PAni was designed as a sensing device in chloroform detection. PAni thin film was synthesized through chemical oxidation method by using aniline (Ani) as a monomer, ammonium persulphate (APS) as an initiator and dioctyl sodium sulfosuccinate (AOT) as a dopant. The chemical structure of PAni thin film was confirmed by using Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectrometer. The conducting behaviour of PAni thin film (1.157 × 10−2 S/cm) was determined by using four-point probe measurement. In the optical sensor part, FBG was etched in hydrofluoric acid solution (48% HF) to remove the cladding layer on fiber before coated with PAni. The response of this sensor was monitored based on the different of Bragg wavelength shift at ∼1557 nm in an optical spectrum analyzer (OSA) detector. PAni-coated FBG significantly increased in the Bragg wavelength shift (sensitivity = 0.0009) compared with uncoated FBG (sensitivity = 0.0002). The interaction between PAni and chloroform was significantly confirmed by the “polaron peak ratio” (Pf/Pi) and “quinoid and benzenoid peak ratio” (IQ/ IB) through UV-vis and FTIR spectroscopy analysis. In this study, FBG sensor coated with PAni thin film had been found as an efficient sensor in chloroform detection with fast response time (7 s).

Chemical Sensors Based on Fiber Bragg Grating

2011 ◽  
Vol 84-85 ◽  
pp. 582-585 ◽  
Author(s):  
Ming Fu Zhao ◽  
De Yi Huang ◽  
Bin Zhou ◽  
Lei Zi Jiao
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Chemical Sensor ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Bragg Wavelength ◽  
Chemical Substances ◽  
Fbg Sensor ◽  
Surrounding Refractive Index ◽  
The Relationship

In this paper, measurement method for the refractive index of chemical substances based on fiber Bragg grating (FBG) sensor was proposed. The relation between Bragg wavelength shift and surrounding refractive index (SRI) was analyzed theoretically and experimentally. The SRI sensitivity of the chemical sensor could be enhanced by reducing the cladding thickness of the FBG using hydrofluoric acid (HF) solution etching process. The experimental results indicated that the variation of Bragg wavelength increased as the SRI increased. In the low SRI region, the relationship between the Bragg wavelength shift and the change of the SRI was approximately linear.

scholarly journals Applying Fiber Bragg Grating for Acoustic Sensor

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Paradorn Pakdeevanich ◽  
Nattapon Likittananan ◽  
Worrapass Promsen
Keyword(s):  
Fiber Bragg Grating ◽  
Sound Intensity ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Intensity Level ◽  
Acoustic Sensor ◽  
Acoustic Disturbance ◽  
Bragg Wavelength ◽  
Fbg Sensor ◽  
Vibration Sensors

In this work, we interested to utilize Fiber Bragg Grating (FBG) for monitoring sound intensity level. Acoustic disturbance could induce strain and changing the refractive index of FBG. Therefore, light will interfere for the trough of transmission at one specific wavelength satisfied Bragg’s condition. In our demonstrations, FBG sensor was perturbed with sound intensity levels of 60, 80 and 100 dB , the measuring Bragg wavelength were recorded at 1552 nm, 1553 nm and 1555 nm, respectively. It was found that the Bragg wavelength shift has a quite linear variation with sound intensity level. In addition, the sensitivity for sensor was 0.0566 nm/dB. The obtained results are promising for developing acoustic and vibration sensors.

Development of Fiber Bragg Grating (FBG) as Temperature Sensor Inside Packed-bed Non-thermal Plasma Reactor

2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Siti Musliha Aishah Musa ◽  
RK Raja Ibrahim ◽  
Asrul Izam Azmi
Keyword(s):  
Fiber Bragg Grating ◽  
Temperature Variation ◽  
Thermal Plasma ◽  
Temperature Sensor ◽  
Plasma Reactor ◽  
Packed Bed ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Bragg Wavelength ◽  
Non Thermal Plasma

This paper presents early work on Fiber Bragg grating (FBG) as temperature sensor to monitor temperature variation inside a packed-bed non-thermal plasma reactor. FBG made from germania-doped fiber with center Bragg wavelength of 1552.5 nm was embedded inside non-thermal plasma reactor with sphere shape dielectric bead (barium titanate) and used to probe the temperature variation inside the reactor. The experimental works have proven that FBG is a suitable sensor to monitor temperature variation inside of reactor via LabVIEW program. Besides that, Optical Spectrum Analyzer (OSA) recorded Bragg wavelength shift as voltage of power supply increases, which indicate the non-uniform temperature variation occurring inside the reactor. However, it does not affect the chemical reaction inside the reactor because the temperature condition is in steady state.

Study on Fiber Bragg Grating Large Current Sensor

2013 ◽  
Vol 823 ◽  
pp. 513-516
Author(s):  
Xin Wang ◽  
Jun Lin Wang
Keyword(s):  
Fiber Bragg Grating ◽  
Rogowski Coil ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Bragg Wavelength ◽  
Large Power ◽  
Giant Magnetostrictive Material ◽  
Large Current ◽  
Current Detection ◽  
Detection Unit

The large power current is sampled by Rogowski coil, then transforms the sampling signals from AC to DC and regulates the signals, the current detection unit is formed with FBG (Fiber Bragg Grating) and GMM (Giant Magnetostrictive Material), the current measurement is achieved based on the F-P interferometer filter demodulation system, finally, linear relationship between the Bragg wavelength shift and external current is validated by experiment.

Fiber Bragg Grating Demodulation System Based on Equi-Intensity Cantilever Beam

2010 ◽  
Vol 437 ◽  
pp. 359-363
Author(s):  
Hong Li ◽  
Wei Ping Yan ◽  
Ren Sheng Shen ◽  
Ben Yu Wang
Keyword(s):  
Fiber Bragg Grating ◽  
Cantilever Beam ◽  
Optical Spectrum ◽  
Optical Signal ◽  
Electrical Signal ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Optical Spectrum Analyzer ◽  
Bragg Wavelength ◽  
Scanning Velocity

Optical spectrum analyzer (OSA) can achieve the higher precision and sensitivity, but it is disadvantageous for translating optical signal into electrical signal. A fiber Bragg grating (FBG) matched filtering system based on equi-intensity cantilever beam was presented in this paper. Strain characteristics in different location of cantilever beam were described, and the strain sensitivity of matching grating demodulation based on equi-intensity cantilever beam was deduced mathematically. Strain characteristics of cantilever beam were verified, and the sensing effect of the system was tested. The Bragg wavelength shift range of the demodulating FBG placed on the cantilever beam reached 10 nm, and scanning velocity was 0.125 nm/s. The system could demodulate slow-altered sensing signal accurately and rapidly.

Monitoring of Microorganisms Growth Process Based on Fiber Bragg Grating Biosensor

2011 ◽  
Vol 84-85 ◽  
pp. 586-589
Author(s):  
Ming Fu Zhao ◽  
De Yi Huang ◽  
Lei Zi Jiao ◽  
Xue Mei Cao ◽  
Xi Han
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Nonlinear Behavior ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Refractive Index Sensitivity ◽  
Bragg Wavelength ◽  
Index Changes ◽  
Index Sensitivity ◽  
The Relationship

The low refractive index sensing principle of the fiber Bragg grating (FBG) was analyzed theoretically, the temperature compensation scheme corresponding to the theoretical model was established. A single-end etched FBG was designed and fabricated for simultaneous measurement of temperature and refractive index. The experimental results demonstrated that the Bragg wavelength shift exhibits a nonlinear behavior with the temperature and yeast refractive index changes. The temperature change to the influence of the sensor was eliminated by numerical analysis, and then the relationship between the Bragg wavelength shift and the yeast refractive index is linear, the sensor yeast refractive index sensitivity of 5.42nm/riu was obtained.

scholarly journals Cladding Modified Fiber Bragg Grating for Copper Ions Detection

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Husam Abduldaem Mohammed ◽  
Aqiel Almamori ◽  
Ali A. Alwahib
Keyword(s):  
Fiber Bragg Grating ◽  
Copper Ions ◽  
Evanescent Field ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Chemical Agent ◽  
Toxic Heavy Metal ◽  
Fbg Sensor ◽  
Fbg Sensors ◽  
Significant Wavelength

This paper reports a fiber Bragg grating (FBG) as a biosensor. The FBGs were etched using a chemical agent,namely,hydrofluoric acid (HF). This implies the removal of some part of the cladding layer. Consequently, the evanescent field propagating out of the core will be closer to the environment and become more sensitive to the change in the surrounding. The proposed FBG sensor was utilized to detect toxic heavy metal ions aqueous medium namely, copper ions (Cu2+). Two FBG sensors were etched with 20 and 40 μm diameters and fabricated. The sensors were studied towards Cu2+ with different concentrations using wavelength shift as a result of the interaction between the evanescent field and copper ions. The FBG sensors showed a good response in terms of significant wavelength shift in corresponding to varying Cu2+ concentrations when immersed in aqueous mediums. The sensors exhibited excellent repeatability towards Cu ions.The results demonstrate that the smaller FBG etching diameter, the better optical response in terms of wavelength and linearity. 

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