A thin fiber optics sensor, VibroFibre, has been developed to fit into a 2 mm gap in transformer windings for directly measuring the winding vibration. The new innovation is aimed to help the transformer users to safely extend service lives of their assets and to mitigate risk of unscheduled shutdown due to premature equipment failure. The optic fiber based vibration sensor can be installed inside a transformer and the resulted vibration measurement is no longer affected by various noise sources from peripheral equipment. The vibration frequency spectrum measured inside an oil-filled transformer, shows a signature of wider band ranging between 20 Hz to 1000 Hz. The new sensor has shown superior performance, especially in its response to frequencies below 100 Hz. When combined with the new Long Gauge technology, the response goes as low as 5 Hz. The sensor’s small size makes it possible to install the sensors in the winding spacers with built-in cradle-like slots, which helps avoid possible disturbance to the cooling oil flow
