A novel fiber Bragg grating based palladium tube sensor was designed for hydrogen leakage detection in aerospace vehicles. The sensor fabrication method was developed and the sensor response was characterized in terms of total wavelength change, response time and degassing ability. Several factors that influence the sensor performance, including the tube thickness, purging temperature, purging gas, hydrogen concentration, and operation temperature, were studied. The sensor response was improved by reducing the thickness of the palladium tube to around 33 micrometer, optimizing the operation temperature to 95 degrees Celsius, and thoroughly degassing the sensor in nitrogen at 95 degrees Celsius for 4 hours. At these conditions, the total wavelength change was about 0.6 nm, the response time (the time to reach a 0.05 nm wavelength change) was about 2 minutes for the four-hour 4% hydrogen tests.
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