Detection of liquid-liquid interface is critical in solvent extraction equipment/contactors typically used in petroleum and hydrometallurgical industries. An instrumentation system, comprising of a self-calibrating ultrasonic sensor and a novel signal processing algorithm is reported. It can be used to estimate location of liquid-liquid interface along with speed of sound in both the liquids without any manual/user intervention. The algorithm involves use of discrete wavelet transform and matched filter. The system has been tested at laboratory scale under wide range of industrially relevant conditions. The system works for any pair of liquid without apriori knowledge of their acoustic characteristics, is insensitive to changes in temperature and/or compositions. It also works for dirty interfaces contaminated with particulate matter or emulsion. The above mentioned features truly impart the sensor system “deploy-and-forget” capabilities. The range, accuracy and resolution of the system, with respect to interface location, are 40–200 mm, 0.45% FS (Full-scale) and less than 1 mm, respectively.

在通常用于石油和湿法冶金行业的溶剂萃取设备/接触器中，液-液界面的检测至关重要。报告了一种包括自校准超声传感器和新颖的信号处理算法的仪器系统。它可以用来估计液-液界面的位置以及两种液体中的声速，而无需任何人工/用户干预。该算法涉及离散小波变换和匹配滤波器的使用。该系统已经在广泛的工业相关条件下以实验室规模进行了测试。该系统适用于任何对液体，而无需先验其声学特性，对温度和/或成分的变化不敏感。它也适用于被颗粒物或乳液污染的脏界面。上面提到的功能确实赋予了传感器系统“部署和忘记”功能。关于接口位置，系统的范围，精度和分辨率分别为40-200 mm，0.45％FS（满量程）和小于1 mm。