本刊78年第5期曾介绍过一种迪克斯公式诺模图。这里所要介绍的是另一种求层速度的计算图(图1),它在原理、制图等方面都较前者简单,使用也较为方便,不须辅助心算就可以直接求出层速度。试用结果表明,这种计算图的精度很容易达到±10米/秒。下面简单介绍一下原理:该图有一固定尺T(时间)和一始终与T尺保持平行的活动尺V(速度)。T尺是均匀刻度的,即其上某一点(设这点的刻度值为t)距O点的距离L(t)是t的线性函数,表示为 This issue of 78, No. 5 has introduced a Dix formula Nom model. Described here is another kind of seeking layer velocity calculation diagram (Figure 1), which in principle, mapping and other aspects of the former than the simple, more convenient to use, without the help of mental arithmetic can be directly calculated layer velocity. Trial results show that the accuracy of this calculation is very easy to reach ± ​​10 m / s. The following is a brief introduction of the principle: The diagram has a fixed ruler T (time) and a movable ruler V (speed) which always keeps parallel to the T ruler. T scale is a uniform scale, that is, a point above it (set the scale value of this point t) from the point O distance L (t) is a linear function of t, expressed as