Nils Theune

Highly sensitive micro-mechanical fiber Bragg grating acceleration sensor combined with a new multiplexable interrogation principle

The paper describes a micro mechanical Bragg grating acceleration sensor with enhanced sensitivity by force amplification. A new multiplexable and affordable interrogation scheme that uses two overlapping Bragg gratings within the sensor will be demonstrated.

Optical monitoring of highly stressed infrastructure and rolling stock modules for railway system operation

For the first time online temperature measurements with FBG temperature sensors on railway overhead lines could be demonstrated. All sensors measured successfully under outdoor conditions over a two year period. As a first experimental result the excess temperatures due to current load are small compared to ambient sources of temperature change. In the future this first result will be analyzed under different seasonal and current load conditions. Furthermore the modeling and first field test have demonstrated the possibility to acquire information about the interaction between OCL and current collector via optical strain gauges integrated into conventional current collector strips.

Novel fiber optic bragg grating acceleration sensor detection scheme

We report on the first results of a fiber optic acceleration sensor which consists of two partially spectral overlapping Bragg gratings. The motion of an inertial mass shifts the Bragg reflections of the gratings in different spectral directions and thus modulates the overall amount of reflected light.

Multiplexed temperature measurement for power generators

This paper reports on the first realization of embedding fiber optical Bragg grating temperature sensors inside the stator bars of a 120 MVA air cooled power generator. Furthermore first measurements of the conductor temperature inside the bushings have been carried out during a generator prototype test run.