High-temperature strain sensor based on sapphire fiber Bragg grating.
Opt Lett
; 49(3): 446-449, 2024 Feb 01.
Article
in En
| MEDLINE
| ID: mdl-38300027
ABSTRACT
Sapphire fiber Bragg grating (SFBG) is a promising high-temperature strain sensor due to its melting point of 2045°C. However, the study on the long-term stability of SFBG under high temperature with an applied strain is still missing. In this paper, we reported for the first time to our knowledge on the critical temperature point of plastic deformation of the SFBG and demonstrated that the SFBG strain sensor can operate stably below 1200°C. At first, we experimentally investigated the topography and the spectral characteristics of the SFBG at different temperatures (i.e., 25°C, 1180°C, and 1600°C) with applied 650â
µÎµ. The reflection peak of the SFBG exhibits a redshift of about 15â
nm and broadens gradually within 8â
h at 1600°C, and the tensile force value decreases by 0.60â
N in this process. After the test, the diameter of the SFBG region decreases from 100 to 88.6â
µm, and the grating period is extended from 1.76 to 1.79â
µm. This indicates that the plastic deformation of the SFBG happened indeed, and it was elongated irreversibly. Moreover, the stability of the Bragg wavelength of the SFBG under high temperature with the applied strain was evaluated. The result demonstrates the SFBG can be used to measure strain reliably below 1200°C. Furthermore, the strain experiments of SFBG at 25°C, 800°C, and 1100°C have been carried out. A linear fitting curve with high fitness (R2 > 0.99) and a lower strain measurement error (<15â
µÎµ) can be obtained. The aforementioned results make SFBG promising for high-temperature strain sensing in many fields, such as, power plants, gas turbines, and aerospace vehicles.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Opt Lett
Year:
2024
Document type:
Article
Country of publication:
United States