基于电-声联合的液膜厚度测量方法研究

Measurement of the Liquid Film Thickness based on an Electrical-acoustic Joint Approach

摘要:

为了拓宽液膜厚度的测量范围,提出了一种联合应用电阻法与超声渡越时间法的液膜厚度测量新方法。设计了新型的电-声复合传感器,建立了用于优化传感器电极结构参数的数值模型,以灵敏度和线性度为优化目标确定了最优电极参数,通过开展液膜厚度测量实验验证了联合测量方法的有效性。研究结果表明：同轴金属电极适合于测量较薄液膜,在2.4mm~4.4mm厚度范围内的相对误差为-4.93%至5.35%；超声探头更适用于测量较厚液膜,在3.4mm~10.0mm厚度范围内的相对误差为-3.68%至2.20%。通过联合应用电阻法和超声法可以拓展两种方法各自的测量范围并且提高测量结果的可靠性。所提出的电学-声学联合测量方法具有测量范围宽、非侵入、响应快、精度和灵敏度高、安全性好等优点,能够广泛适用于工业生产和实验室研究等场合。

Abstract:

To widen the measuring range of liquid film thickness, a new approach combining resistance-based method and ultrasound-based method is proposed. A new type of electrical-acoustic composite sensor was designed, and a numerical model was established to optimize the electrode structure parameters. The optimal electrode parameters were determined with the sensitivity and linearity as optimization specifications. The validity of the joint measurement approach was verified by the liquid film thickness measurement experiment. It has been demonstrated that: the coaxial metal electrode is suitable for measuring a thinner liquid film, and the relative error ranges from -4.93% to 5.35% in the thickness range of 2.4 mm to 4.4 mm; the ultrasonic probe is more suitable for measuring a thicker liquid film, and the relative error ranges from -3.68% to 2.20% in the thickness range of 3.4 mm to 10.0 mm. The measurement range of the two methods can be expanded and the reliability of the measurement results can be improved through the combination of the resistance-/ultrasound-based methods. The proposed method has the advantages of wide measurement range, non-intrusive, fast response, high accuracy and sensitivity, and good safety, which can be widely used in industrial production and laboratory research applications.