MEASUREMENT OF FLOW SPEED

摘要

PURPOSE:To make it possible to certainly measure a flow speed within a short time in a shallow sea area, in a case for measuring a flow speed on the basis of the reflected wave of the ultrasonic pulse transmitted into seawater, by regulating the transmission cycle of the ultrasonic pulse in matching relation to the depth of water. CONSTITUTION:The ultrasonic pulse generated by a transmitter 1 is transmitted into seawater from a transmitter receiver 2 and the reflected wave thereof is caught by the transmitting receiver 2 to be inputted to a receiver 4. The output signal of the receiver 4 is inputted to a sea bottom signal detection part 5 to detect the depth of water and the delay time corresponding to the degree of the depth of water is set by a delay circuit 6 to supply a transmission trigger signal to the transmitter 1. The output signal of the receiver 4 is also inputted to an earth speed detection part 7 and a speed-to-water detection part 8 and the difference between both speeds is calculated by an operator 9 and subsequently receives averaging operation in an averaging part 10 to calculate a flow speed.