| 摘要 |
PROBLEM TO BE SOLVED: To provide an antenna whose maintenance can be executed without stopping traffic. SOLUTION: Measurement data by a sensor 10 measuring the flow rate of water flowing in a water pipe 4, which is fitted to a valve 5 installed in the water pipe 4 is supplied to radio equipment 12 through a data line 11 and measurement data by the sensor 10 is transmitted from a transmitter in radio equipment 12. The transmission signal is transmitted through a feeder 13 and is supplied to the rear face of a manhole cover 2 from a feeding part 14. Thus, the manhole cover 2 is excited by the transmission-signal and measurement data is transmitted from the manhole cover 2. Thus, measurement data on the sensor 10 can be transmitted without opening the manhole cover 2. |
