| 摘要 |
A sensor device has a pressure sensor (10), a processing unit (20), a housing (30) having formed therein an inlet hole (31) for guiding a fluid to be measured to the pressure sensor, and a vibration unit (40, 204) for generating, in the inlet hole, a standing wave having a resonant frequency determined by the shape and condition of the inlet hole by causing the fluid to be measured in the inlet hole to vibrate. One end of the inlet hole is open, and the other end is closed. At the closed end of the inlet hole, the pressure sensor is provided in the housing so as to be capable of detecting the pressure of the fluid to be measured within the inlet hole. When the standing wave is generated in the inlet hole by the vibration unit, the pressure sensor outputs an electric signal that has a periodically varying amplitude and corresponds to the resonance frequency. On the basis of the frequency of the pressure-sensor electric signal corresponding to the resonance frequency, the processing unit determines whether the inlet hole has been blocked by foreign matter. |
