• Faser Bragg Gitter

The fibre Bragg Grating (FBG) - principle:

The light from a broadband wavelength spectrum is coupled into the fibre optic sensor, while a single wavelength out of it is reflected and analyzed in an evaluation unit. This wavelength is directly correlated to the actual state of the sensor concerning its temperature resp. mechanical stress.

Since there is no electrical energy at all at site of measurement, thesesensors are optimally qualified to be placed in explosive areas, as well as in humid or EMI (electromagnetic interference) loaded zones.

The principle of measurement opens new applications for a wide range of both geophysical and structural engineering studies.
The most outstanding advantage of these sensors is their long term stability, so that they can be integrated into structures without any need of further calibration over their whole lifespan. Additional installation is also possible. This system is often used for monitoring and controlling functions in the field of buildings and other critical structures.

We introduce a novel system for monitoring strain, vibration and temperature based on optical fibre technology. This system has been developed for applications like long term structural health monitoring (SHM) for civil and industrial structures.
It is used to measure strain, displacement and vibrations. This system provides new perspectives for a detailed interrogation of various seismic or geophysical events and/or for measurements on buildings, bridges,power plants and other structures.

Compared with other techniques, the most important advantage of the sensors is its long term stability. If necessary, most of the sensor designs can be directly integrated into structures. Once applied, there is no need for any calibration or maintenance of the sensor during its whole lifetime.

Alternatively, the sensors can be fixed on already existing structures. Especially the immunity of the Bragg sensor against electric and magnetic fields qualifies the FBG measurement system for critical industrial applications. Thus the interrogation system is often used for monitoring and controlling of power generation and power transmission. Further fields of application are automotive engineering, aerospace industry, high temperature monitoring and SHM of composite materials.