Fibre Optic Strain Gauges

Fibre Optic Strain Gauges are utilised as essential structural health monitoring tools in various industries. They are based on Fibre Bragg Grating (FBG) technology, which minimises noise, eliminates the need for electrical power supply for operation and enables long-range measurements.

When an external compression or stretching force is induced in the fibre, it is subjected to positive or negative strain. As a result, the interval at which the fibre-grating interference are placed will change. It will lengthen if the fibre is stretched and shortens if the fibre is compressed. This change will alter the time required for the reflected light to travel back which also changes the Bragg’s wavelength. The change in the Bragg’s wavelength is proportional to the strain induced in the fibre. The results can be transmitted to the Fibre-Bragg Interrogator for analysis and signal conditioning.