音叉式液体密度计测量仪的设计

Design of Tuning Fork Liquid Density Measurement System

针对现有液体密度检测方法的不足,提出了一种音叉式液体密度测量方法。根据音叉的振动频率随音叉叉臂间的液体密度改变而改变的原理,利用压电陶瓷的压电效应,用电压信号驱动激励压电陶瓷来使音叉振动,同时拾振压电陶瓷拾取振动信号并转化成方波信号。通过测量该方波信号的频率就能测出液体密度,并据此设计了一套音叉式密度测量仪。该音叉式密度检测方法较适合于液体密度的检测,检测精度高、且直接在检测点上将液体密度转化成了频率,便于数字化,且精度高,操作简单,大大提高了检测效率,可以满足高精度液体密度测量要求。

Aimed at the shortcomings of the existing methods of liquid density measurement,this paper brings out a new way of tuning fork liquid density measurement.This design is according to the principle that the vibration frequency of the tuning fork changes when the medium between the arm of the tuning folk is different.According to the piezoelectric effects of piezoelectric ceramic,a voltage can be applied to the piezoelectric ceramic and convert the voltage signals into mechanical vibrations,drive the tuning fork to produce vibration.At the same time the receiving piezoelectric ceramic can pick up the vibration of tuning fork,and convert mechanical vibrations into square waveform signals.A set of tuning fork density measuring instruments are designed depends on the principle for calculating the liquid density by measuring the frequency of the square waveform signals.The circuits are simple structures,high integration,low power consumption and stable performance,easy to extract relevant characteristics.It can meet the requirements of high precision liquid density measurement.