用声波方法测量液体密度的实验研究

Experimental research on the liquid density measurement by acoustic wave method

将平板放在不同密度和粘度的液体中,用声源在平板的侧面激发声波,该声波沿平板传播并通过上、下界面耦合到液体中,其传播特征受液体密度、速度和粘度的影响。该影响通过声波传播速度和幅度表现出来。通过测量液体中沿平板表面传播的声波速度随频率的变化关系,可以得到液体的密度和速度特征。文章用实验的方法对其进行了研究:将平板放在两种不同密度的油中,测量了波形,对比了所测量波形的速度随频率的变化关系,直观显示了两种不同液体中所测量波形速度的差别。

Acoustic wave is excited by an acoustic source in the side of a plate which is in different kinds of liquid in density and viscosity.It transmits along the plate and is coupled to liquid through the upper and lower interfaces of the plate. The transmission of the acoustic wave varies in velocity and amplitude according to the density,velocity and viscosity of the liquid.The characteristic of the liquid's density and velocity can be calculated by measuring the change of the velocity of the acoustic wave transmitting along the interface between the liquid and the plate according to frequency.This paper researches the problem with the experimental method as follow: put a plate into two kinds of liquid with different density,measure the waveforms,compare the changes of the velocity of the waveforms according to frequency,show the difference between the waveforms measured in the two kinds of liquid directly.