| 摘要 |
PURPOSE:To make it possible to determine the contnt of the drum of a concrete mixer accurately any time and to make concrete depositing work efficient, by combining a sound-wave input and output means with a control device. CONSTITUTION:When ready-mixed concrete is discharged from a drum 1, a control device 4 and a sound input and output means 3 are operated. A transmitter 5 transmits signals corresponding to frequencies from a low region to a high region. A sound wave is transmitted into the drum 1 by the means 3 in correspondence with the signal. The reflected wave is collected. The input signal caused by the reflected wave is sent to a detector 7 through a receiver 6. A resonnance level corresponding to the content in the drum 1 is compared with a present resonance level corresponding to a preset content. Thus the content of the drum 1 is determined, outputted to terminal devices 9 and 10 through an operator 8, and reported to the operator and the like. |
