| 摘要 |
PURPOSE:To obtain the depth of water and water temperature easily by using two ultrasonic wave receivers arranged at a specific interval and one temperature detecting element by utilizing the specific correlation among the propagation speed of an ultrasonic wave in water, refraction, and water temperature. CONSTITUTION:The ultrasonic wave receiver 1 and nondirectional receiver 2 are arranged at the specific interval L to detect echo times tD and tDD respectively. The temperature detecting element 3 detects the surface layer water temperature T1. When the depth of water is denoted as H, water temperature of a high layer above H/2 is denoted as T1 deg.C, and that of a lower layer is denoted as T2 deg.C, speeds c1 and c2 of the ultrasonic wave in the layers are calculated from the Willson experimental equation. Further, a relational expression is derived among said tD and tDD, H and L, T1 and T2, c1 and c2, and theta1 and theta2 in a figure, so the equation is solved by an arithmetic circuit 4 to obtain T1 and T2, H, etc. The results are displayed on a display device 5. |
