Palladium and its alloys show a high and selective affinity for hydrogen, resulting in a volume expansion. Fibre Bragg gratings attached to palladium elements are used to monitor the resultant strain from the hydrogen uptake. The technique is aimed at low concentration hydrogen monitoring to a few hundred ppm, where H2 is the result of ageing of polymer materials. We demonstrate a sensor exhibiting 10 ppm sensitivity and report on observed cross sensitivity to environmental conditions. © British Crown Copyright 2006/MOD.
- Fibre Bragg grating
- Fibre optic sensing