Distributed excess strain sensor using fiber Bragg gratings

摘要

For some applications there is no necessity in precise measurement of external influence strength. Sometimes, for early warning and alarm systems, it is sufficient to detect appearance of the monitoring variable within some predetermined interval. A system must generate an alarm signal when the monitored parameter approaches near or crosses the limit of the dangerous zone. For such applications, we propose a simple distributed sensor based on a large array of equal Bragg gratings. An interrogation of the sensor is performed at a fixed wavelength. We discuss a principle of operation of the sensor and present results of experimental demonstration of this technique for distributed detection of gasoline leak.