一、引言在海洋调查中,我们往往把探测海洋要素的探头放在海里(水面或海底),再通过很长的电缆将探头感应到的信号送到船上或观测点。本文就是针对探头中的前置放大器进行讨论。这部分海洋仪器,由于探头连接的电缆很长(从数十米到数百米),探头接收到的信号又十分微弱,因此我们利用前置放大器将探头接收到的微弱信号予先放大。前置放大器是海洋仪器的关键部分,它一般可用方块图(一)表示。例如走航自记的《海空核子旋进式磁力 I. INTRODUCTION In marine surveys, we often place probes that detect elements of the ocean in the sea (on the water surface or the sea floor) and then send the signals sensed by the probes to the ship or observation points through very long cables. This article is for the probe in the preamplifier to discuss. This part of the marine equipment, the probe connected to the cable is very long (tens to hundreds of meters), the probe receives the signal is very weak, so we use the preamplifier to receive the weak signal probe to enlarge. The preamplifier is a key part of marine instrumentation and can generally be represented in block diagram (I). For example, sailing self-recorded "sea nuclear nuclear precession magnetic force