一、概述几十年来尽管很多国家都在研究非声学的水下探测方法,但就目前来讲,声波仍是水下探测的主要手段。回声测深仪是利用声波在水中传播的物理特性来实现水深测量的。当前显示水深的方式有直读式和记录纸式两种。数码管式是直读测深仪的一种,它是选用按一定频率要求的、稳定性很高的石英晶振,以它固有的频率作为信号源,经将每个周波整形成方波、以此作为测量水深的最小单位。用发射的触发脉冲信号和接收到的回波信号作为门控的开门和关门信号,在开、关门之间所累计的方波数即为水深。我们知道声速随水温的变化较大、要使晶振频率完全适应这一变化的要求亦比较困难,加之它的抗干性差、若需记录得配上打印设备、这样则过于复杂、故未能在河道、水库水深测量中被广泛采用。记录纸式测深仪有直线和园周两种时基记录方式,其原理是相同的,即记录发声和收到回声之间笔尖转动的线速度或角速度来表示被测水的深度。由此可见笔尖旋转速度的稳定对测量水深的准确性起着决定性的作用。由于这类仪器抗干性强、能直观河床形状、容易作到使笔尖转速适应声速的变化、故在水深测量方面至今仍被普遍采用。这类记录纸式的测深仪器、从当前国内生产或较早进口的一些测深仪来看多采用齿轮箱变速、离心调速。它的稳速 I. Overview Although many countries are studying non-acoustic underwater detection methods for decades, for the time being, acoustic waves are still the primary means of underwater exploration. Echo sounder is the use of sound waves in the water to spread the physical characteristics to achieve the depth measurement. The current way to display the depth of direct reading and recording paper two. Digital tube is a direct reading depth sounder, it is the choice of a certain frequency requirements, high stability of the quartz crystal, with its inherent frequency as a signal source, after each cycle shaped into a square wave to This is the minimum unit for measuring water depth. With the launch of the trigger pulse signal and the echo signal received as a gated open and close signal, the square wave number between the open and close the door is the depth. We know that the speed of sound varies greatly with the water temperature. It is also difficult to completely adapt the frequency of the crystal to this change. In addition to its poor anti-drying property, it is too complicated to record if it is equipped with a printing device. Therefore, River, reservoir depth measurement is widely used. The recording paper depth sounder has two time base recording methods: straight line and roundtable. The principle is the same, that is, recording the linear velocity or angular velocity of the nib rotating between the echogenic and echogenic to indicate the depth of the water to be measured. This shows that the pen tip rotation speed of the water depth accuracy of the measurement plays a decisive role. Due to the strong anti-drying ability of these instruments, the shape of the river bed can be intuitively realized, and the speed of the pen tip can be easily adapted to the change of the speed of sound. Therefore, the measurement of the water depth is still commonly used. This type of recording paper-type sounding instruments, from the current domestic production or earlier imported sounder point of view more gearbox speed, centrifugal speed. It’s steady speed