| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluctuation pressure sensor suitable for the detection of a slight pressure fluctuation such as the detection of a vibration pressure in a flow meter by a fluidic type fluid oscillator or a Karman's vortex flow meter. SOLUTION: A piezoelectric element stuck with a piezoelectric body of a plastic film having electrode layers on both faces to a planar base is pinched and held by two vessels each having a recessed void of the same shape on the inside of an annular edge section. A groove is formed at the edge section of each vessel having the void, and an elastic gasket is stored in it. The elastic gaskets are kept in contact with the inner peripheral walls of the grooves at an air gap with the outer peripheral walls of the grooves before the piezoelectric element is pinched and are held by the vessels having the voids across the piezoelectric element. The elastic gaskets are deformed toward the outer peripheral walls of the grooves to strain the piezoelectric element, and a fluid pressure is introduced from fluid guide ports provided on the recesses of the vessels having voids, respectively.
|
