介绍了采用声学直接测量方法进行声速测量的声速剖面仪原理 ,声速仪标定的必要性、标定原理和方法 ,以及系统组成和指标。探讨了声速偏差与深度误差的关系 ,使用声速仪对测深仪进行了声速改正的试验。 This paper introduces the principle of sonic velocity profiler using acoustical direct measurement method, the necessity of calibration of sonic velocity meter, principle and method of calibration, as well as the system composition and index. The relationship between the velocity deviation and the depth error was discussed, and the sonic velocity sounder was calibrated using a sonic velocity meter.