振弦传感器的对偶数字化变送器

针对振弦传感器应用中受电缆长度影响的问题,设计利用嵌入CPU的PWM输出功能,产生扫频现地激励传感器振弦,振弦受激励后,谐振的频率在现地经过嵌入的信号调理电路,自动增益检波,精确地检测振弦的谐振频率,实现1个对偶配套的振弦传感器数字化、隔离化、网络化变送器.变送器完成测量频率与对应物理量变化的实时数字转换,并通过隔离RS485通信输出.经过在某金属结构稳定观测系统的应用,证明该变送器的性能达到了预期目标,是一种新型的对偶变送器.

Study on a smart signal processing transformer to vibrating wire transducers

This paper introduces a type of newly developed integrated transformer that converts the vibrating wire sensor＇s （VWS） resonant frequency output to digital RS485.The transformer takes advantage of embedded CPU＇s PWM pulse function to excite the VWS＇s wire which output sweep frequency vibrating from 400 Hz to 5 kHz,meanwhile,monitoring the output of the occurring of wire resonant frequency by the smart self gain amplifier and digital filter.As digital RS485 feature,a series of VWS can be chain linked up to 32 using only one RS485 cable and the same power source.Application of the transformer in a dam security monitoring system proves the transformer is a great match to VWS applications.