| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid surface state monitoring device capable of reducing the burden of maintenance.SOLUTION: A storage section 23 stores air temperature and water temperature of a reference point. A temperature measurement section 21 measures temperature of an optical fiber sensing cable 1 installed in a sewer 100 at a prescribed position. A determination section 24 compares the air temperature and water temperature stored in the storage section 23 with the temperature measured by the temperature measurement section 1, and determines whether or not a liquid exists at the prescribed position on the basis of the comparison result. As a result, a device with a complicated structure, such as a traditional water level sensor, is unnecessary because temperature detection by the optical fiber sensing cable itself is a principle of temperature measurement. Thus the burden of maintenance of a detection section can be reduced. |
