| 摘要 |
PURPOSE:To minimize errors in depth to the surface of sludge and the bottom of water by attaching a delay circuit to a system of receiving sound wave. CONSTITUTION:Variable delay circuits 21 and 22 added are connected to amplifiers 15 and 16 and then, to a record amplifier 17 through a variable switch. Two different frequencies fH and fL pass through the delay circuits 21 and 22 to delay the received wave signal for the correction of the time delay in the receiving system, which enables a recording with limited depth errors. The delay circuit 21 or 22 are given a preset delay value, which is adjusted with a rigid body placed under water and as a signal reflected from the rigid body will not vary with the frequency, it indicates the same depth. Thus, errors in the electric system can be minimized by adjusting and calibrating the delay circuits 21 and 22 so that depth values may appear at the respective fixed position on the record. |
