| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid level deterioration detection device for accurately detecting the level of a liquid surface and the degree of deterioration using a simple constitution. SOLUTION: The oil level deterioration detection device 1 has an ultrasonic sensor 7 at a bottom section 5 of a container 3 having oil. A transmission side electrode 17 is provided at the side of a diaphragm 15 of a piezoelectric element 11, and a pair of signal side electrodes 19 (an electrode 19a for detecting deterioration and an electrode 19b for detection a level) is provided on the opposite side. Especially the transmission side electrode 17, that is provide at the side of the diaphragm 15 of the piezoelectric element 11, is formed into a disc shape, but the electrode 19a for detecting deterioration and the electrode 19b for detecting a level being provided at the opposite are in a semi-circular shape, where a circle is cut at the center. Also, a reflection section 27 for reflecting ultrasonic waves is provided at the outside of the diaphragm 15, and has a reflecting plate 27a, a support section 27b, and a region separation plate 27c. |
