Design Of High Precise And Wide Span CTD Measurement System

Because of the direct impact of underwater navigation safety and tactical and technical action,the temperature,conductivity(salinity)and submergence depth of sea water are important parameters that must be measured and paid attention to in underwater vehicle underwater navigation.The underwater vehicle must carry such measurement equipment to ensure that these parameters can be obtained in real time.A high precision temperature and salinity measurement system is designed in this paper to measure seawater temperature,conductivity and pressure.Then the salinity of the sea water and the submersible depth of the submersible are calculated according to the navigable waters.Considering the special requirement that the sensor should be installed outside the cabin and the scope of navigation,the pressure resistant hatch of the sensor is designed at a high depth(high pressure resistance),and the measurement range of the conductivity and pressure(depth)sensor is designed for a large range of range design.According to the function and performance requirements of the system,the structure design of the system sensor is put forward.It mainly includes sensor probe,pressure sealed cabin,electrical connector and protective cover.The shape,strength and installation method of the high pressure cabin are designed in detail,and the design results of the main components are given.In hardware circuit,the passive hardware + three templates are adopted in the system hardware circuit.Based on the study of the working principle of conventional temperature,electrical conductivity and pressure sensors,the selection of sensitive elements is made,and the installation mode of sensitive elements is designed according to the overall scheme of the sensor.The signal conditioning circuit and the letter are designed according to the principle characteristics of the three sensitive elements and the special requirement of the high precision range of this system.Signal acquisition,data processing and quality control hardware circuit and corresponding control,measurement and data processing software.On the basis of the completion of the system structure and circuit and the design of the corresponding software,the prototype system is manufactured and tested.Compared with the conventional import commercial system,the results show that the performance index of the system is close to that of the system.After further testing and improving the manufacturing process,it is expected to replace the import.