| 摘要 |
PROBLEM TO BE SOLVED: To correctly measure a water level even when the water level momently changes, or even in turbid waters or a billow caused by bad weather. SOLUTION: A communication unit 13 conducts the reception of a control instruction from a control department and the transmission of a measured result of the water level. A power source unit 12 supplies an electric power to all units within a device. A measuring electronic circuit 11 radiates leaser beam emitted from a light emitting device 12 to a water surface of a measuring object and receives a reflected wave from the measuring object. The time difference between the radiate time of radiated laser beam and the received time of the reflected wave, or the difference of a physical quantity held in a modulating signal of the irradiated laser beam and a physical quantity held in the modulating signal of the reflected wave corresponding to the laser beam are used to calculate the water level. In addition, the water level is determined from the distribution of the measured results of water level measurement repeated plural times. |
