4~20 mA压力变送器的研制

Development of 4~20 mA Pressure Transmitter

针对生产过程参数在线监测系统的需求,设计了测量水网管线压力的4~20 mA压力变送器。该变送器采用国产NSA2860芯片作为整个系统的核心,在线监测水网管线压力参数,将监测到的压力转化为4~20 mA的电流信号送入附近的RTU中,RTU通过以太网将压力参数传输到石化控制室进行集中显示,实现参数超限报警。着重介绍了压力变送器供电、传感器激励、环境温度采集、输出V/I转换、通信电路、机械结构、系统校准补偿和测试结果。该变送器具有使用简单、可靠性好、采集压力精度高等优点。

According to the monitoring requirement of on-line monitoring system for production process parameters,this paper introduces a kind of 4~20 mA pressure transmitter designed to measure the pressure parameters of water pipeline.The transmitter adopts NSA2860 as the core of the whole system to monitor the pressure information online,converts the pressure parameters into 4~20 mA current sigmals and sends them to the nearby RTU,and the RTU transmits the pressure signals to the petrochemical control room through Ethernet for centralized display,so as to realize the parameter overrun alarm.This paper introduces power management,sensor excitation,ambient temperature acquisition,output V/I conversion,communication circuit,mechanical structure,system calibration compensation and test results of the pressure transmitter.This transmitter has the advantages of simple use,good reliability,high accuracy of pressure measurement.