| 摘要 |
This application discloses an apparatus configured detect a physical quantity, for example a density, of a flowing fluid, the apparatus including: - a sensor body (2) configured to extend into the flowing fluid, the sensor body comprising a fiber Bragg grating (FBG) of a fiber Bragg grating sensor (3, 7, FBG), for generating a detector signal relating to vibration of at least part (2B) of the sensor body (2); and - a processing unit, configured to process the detector signal, and to determine the physical quantity based on detected vibration at a mechanical eigenfrequency of the flexible part (2B) of the sensor body (2). |
