用于微弯型科氏质量流量计的数字变送器研制

Development of digital transmitter for micro-bend type coriolis mass flowmeter

针对微弯型科里奥利质量流量计固有频率高且相位差小等特点,将带通滤波器和二次Lagrange插值的数字式过零检测方法相结合应用于传感器的信号处理。以TMS320F28335为核心,研制科氏质量流量变送器,实时实现整套算法。给出了变送器系统软、硬件设计方案,并对变送器进行了系统测试和现场标定实验,在40:1量程比范围内,标定精度优于0.1%。测试数据表明,整套算法简单、有效,所研制的变送器具有较高的测量精度。

To solve the problem of micro-bend type Coriolis mass flowmeter＇s high intrinsic frequency and small phase difference,a method consists with IIR band-pass filter and digital zero-crossing detection using Lagrang＇s interpola-tion is proposed in this paper.The whole algorithm is implemented in real time on a Coriolis mass flow transmitter devel-oped with TMS320F28335 chip.The design schemes of hardware and software are presented,system tests and water flow calibrations were also performed while the relative error is lower than 0.1% with range-ratio upto 40：1.Experimental re-sults show that this algorithm is easy and effective,and the transmitter possesses high accuracy.