Measurement Of Liquid Concentration Based On Ultrasonic Velocity And Acoustic Attenuation

Ethanol is an important chemical solvent and raw material for production,is widely used in chemical industry,food,medicine and other industries.With the rapid development of ethanol industry in our country,the ethanol concentration can be real-time on-line detection in the actual industrial production process.Due to the direct use of chemical measurement methods generally require artificial long time,It is difficult to meet the needs of real-time control of production.With the rapid development of industry,there is an urgent need for automatic,rapid,and inexpensive methods for measuring the characteristics of liquid foods with low cost and nondestructive measurement.Comparedwith other measurement techniques,ultrasonic liquid measurement technology has obvious advantages,it is of great practical value to develop intelligent on-line measuring instrument for alcohol concentration.First,the hardware circuit design of ultrasonic excitation and echo,mainly consists of transmitting circuit,transformer amplifier,echo amplification and band-pass filter circuit,AD data acquisition card dual channel to achieve the ultrasonic send the specified number of 1MHz excitation signal waveform data acquisition using the 16 bit,25MHz,you can set the acquisition card the sampling frequency and sampling depth parameters such as the use of PC software.Secondly,the level threshold method is used to locate the starting point of the transmitted wave in the data acquisition,and a linear fitting method is proposed for the location of the echo starting point,which is proved to be effective and feasible through experimental verification.Finally,the functional relationship between sound speed and concentration,the attenuation coefficient and the concentration in pure water and different concentrations of ethanol solution were analyzed by experimental data.The concentration measurement model based on sound velocity and temperature was obtained by interpolation.Analysis of the function relationship between the measuring error and the sound velocity method concentration model attenuation coefficient,attenuation coefficient compensation reduces the error of concentration measurement by acoustic experiment method is by concentration velocity method and attenuation of the accurate measurement of ethanol,and is stable and feasible.