| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique that prevents a liquid from contacting a piezoelectric element.SOLUTION: Provided is a liquid level detection device 10 comprising: a propagation member 20 for propagating a surface wave and provided in a container 70 so as to be immersed in a liquid; vibration generation detection means 50 for applying vibration to the propagation member 20 and equipped with a piezoelectric element 51 for detecting a reflected surface wave W1; and level detection means 60 for calculating a liquid level from the reflection time of the surface wave. The propagation member 20 consists of a resin material, and is provided integrally with an element accommodation part 30 for accommodating the piezoelectric element 51 at the top, the element accommodation part 30 having a bottom face 32 formed in such a way that a portion of it protrudes from a principal plane 23 constituting the surface of the propagation member 20. The piezoelectric element 51 is disposed in such a way that a portion of it protrudes from the principal plane 23 and vibration is applied in the vertical direction to the principal plane 23 via the bottom face 32.EFFECT: The vibration of the piezoelectric element can be applied to the propagation member, making it possible to prevent a liquid from contacting the piezoelectric element.SELECTED DRAWING: Figure 2 |
