Distributed hydrogen sensing using in-fiber Rayleigh scattering

Abstract

This letter reports a fully distributed hydrogen sensing technique using Rayleigh backscattering in palladium (Pd) and copper (Cu) coated optical fiber. The local in-fiber strain changes due to Pd hydrogen absorptions are interrogated spatially resolved optical frequency domain reflectrometry measurements of the Rayleigh signals. Electrical power is used to induce heating in the Pd coating, which accelerates both the hydrogen response and the sensor recycling. This technique promises an inexpensive and truly distributed fiber solution for continuous hydrogen leak detection with centimeter spatial resolution at room and low temperatures.

Towards label-free distributed fiber hydrogen sensor with stimulated Raman spectroscopy

“…To prepare hydrogen with concentration of 1%, 2%, 4%, 6%, 7.9%, 10%, 15.2%, 20%, the flow rate of pure hydrogen was set to 5 sccm (standard cubic centimeter per minute) and the flow rate of pure nitrogen was set to 495, 245, 120, 78, 58, 45, 28, 20 sccm. The time of gas filling into the gas chamber was 4,11,15,22,29,36,55,72 minutes, respectively. After the gas filling process, the gas chamber was sealed.…”

Variable-temperature Raman spectroscopic study of the hydrogen sensing mechanism in Pt-WO3 nanowire film

“…Besides, hydrogen-based energy is a clean and renewable alternative to carbon-based fuels and is actively explored by many researchers. [1][2][3][4][5] For safety reasons, hydrogen leak detection, either for concentration of 0%-10% H 2 in ambient or for the process control in concentrations near 100% H 2 in the industrial productions, becomes important issues. Metal oxide semiconductor (MOS) sensors are widely used for hydrogen safety applications due to their small sizes and possibility of mass production.…”

Distributed hydrogen monitoring with phase-sensitive optical time-domain reflectometry

“…These merits make DFS an attractive candidate for distributed hydrogen sensing. Several DFS systems for hydrogen detection have been reported [2][3][4], however, their performance is limited. In [2], the sensitivity is relatively low since the system is based on the loss of the pulse; in [3,4] the sensing range are very limited because of the large loss of the acoustic wave propagating along the fiber [3] and the coherence of the laser [4].…”