| 摘要 |
PROBLEM TO BE SOLVED: To provide a practical fluid-proof ultrasonic sensor not deteriorating even when a gas component is liquefied when used in the presence of petroleum gas, having high sensitivity when applied to a flowmeter, and capable of executing highly accuracy measurement. SOLUTION: In this fluid-proof ultrasonic sensor, a high-frequency type sensor element for transmitting/receiving a high-frequency ultrasonic wave is stored in a fluid-tight case comprising a matching layer and a case body, and the sensor element executes transmission/reception through the matching layer. In the sensor, the matching layer comprises an oil resistant material, and the matching layer is mounted fluid-tightly on the case body via a material having elastomeric property and oil resistance. |
