| 摘要 |
PURPOSE:To improve the accuracy of measurement by arranging an air chamber on one side of a vibrator made up of piezo-electric elements pasted in such a manner as to have a through hole closed by a net-like body on the wall surface facing it while bringing the other side thereof into contact with water or the like. CONSTITUTION:A vibrator 4 having a disc-shaped piezo-electric element 2 pasted on one side of a metal disc 1 is mechanically mounted on the wall surface 11 of a water tank in such a manner that the surface of the metal disc gets into contact with water. If the water pressure in the water tank changes, with a force applied in the direction of the arrow 10, the vibrator 4 outputs a voltage corresponding to the force from a terminal 5. On the wall surface 11 of the water tank, an air chamber 13 is provided behind the vibrator 4 with a fitting 7 and a screen-shaped body, for example, metal screen 9 closes a small through hole 8 provided on a wall facing it. When specified dimensions are selected for individual parts, flat frequency characteristic can be expanded 3<1/2> times without reducing water pressure voltage sensitivity. This can improve the measuring accuracy with a simple construction. |
