Hydrogen FBG sensor using Pd/Ag film with application in propulsion system fuel tank model of aerospace vehicle

Abstract

The high efficiency hydrogen fiber Bragg grating (FBG) sensor is presented. The sensitive film was a new alliance of palladium-silver (Pd-Ag). In addition, the titanium (Ti) layer was used as the adhesive layer. The presented sensor showed the resolution of more than 60 pm/1% H 2 , and a fast response time of 4 s-5 s was guaranteed in the 0.1% H 2-4% H 2 range. Moreover, the life time of the sensor was investigated. The obtained results showed that the sensor had an enhanced life time. Furthermore, the sensor was applied in the propulsion system fuel tank model of the aerospace vehicle. The obtained results indicated that it is a prevention system against the disaster aerospace due to hydrogen leakage.

Manufacture, Applications, and Opportunities of Thin Film Palladium-Silver (PdAg) Alloys: A Review

“…20 Certain applications may use materials prepared a single manufacturing technique, as the properties essential end use of the material are closely influenced by the preparative route. For example, PdAg thin films for sensor applications are commonly prepared using CVD or PVD, 36,[65][66][67][68][69][70][71][72][73] while those for use in gas separation may use electroless deposition 14,22,28,31,35,[74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89] or mechanical methods 14,33,85,[92][93][94] though this is not exclusive.…”

“…65 Several researchers have demonstrated the sputtering of PdAg alloys using separate targets of Pd and Ag. 14,32,[75][76][77][78] PVD methods are used extensively to prepare PdAg films for sensor applications, [65][66][67][68][69][70][71][72][73] and to a lesser extent, for gas-permeable membranes. 81,135 Chemical vapour deposition (CVD, Figure 3) uses thermally labile precursors which are decomposed by heat to produce thin films of metals, oxides or other compounds on a substrate.…”

Dissolved hydrogen detection in power transformer based on etched fiber Bragg grating

“…Many researchers have developed FBG hydrogen sensors based on pure palladium or related alloy as the hydrogen sensing membrane coating on the surface. However, most of them are utilized to detect hydrogen leakage and the minimum concentration is only set about 0.4% [8,[15][16][17]. Early our team members have researched high sensitive and reliable fiber Bragg grating hydrogen sensor aiming to dissolved hydrogen detection especially in oil-immersed power transformers [11,12], while factors of sensor fabrication have not considered carefully.…”

Polyimide-coated fiber Bragg grating for relative humidity sensing

“…The fiber Bragg grating (FBG) has been extensively investigated and very widely applied in many fields [1][2][3][4][5][6][7]. Compared to conventional capacitive and resistive humidity sensors, the FBG coated with polyimide (PI) used for humidity sensing has unique advantages in terms of high temperature resistance, corrosion resistance, high measurement accuracy, miniaturization, etc.…”

“…The fiber Bragg gratings coated with various sensitive materials have been applied to measure different kinds of samples such as hydrogen, and also for ultrasonic [4,6] and humidity sensing [8,9]. Some experiments have verified the excellent linear relationship between the relative humidity and Bragg wavelength shift of the FBG coated with the moisture sensitive material, e.g., PI [10].…”