This paper reports on a new system for liquid density and viscosity measurement based on a freely suspended rectangular vibrating plate actuated by piezoelectric ceramic (PZT) actuators. The Lamb mode used for these measurements allows us to infer both the density and viscosity in a larger range as compared to the existing gold-standard techniques of MEMS resonators. The combination of the measured resonance frequency and quality factor enables extraction of density and viscosity of the surrounding liquid. The system is calibrated while performing measurements in water glycerol solutions with a density range from 997 to 1264 kg/m³ and viscosity from 1.22 to 985 mPa·s, which is a larger dynamic range compared to existing mechanical resonators showing an upper limit of 700 mPa·s. The out-of-plane vibrating mode exhibits quality factor of 169, obtained in deionized water (1.22 mPa·s viscosity), and 93 for pure glycerol with a viscosity of 985 mPa·s. This Lamb wave resonating sensor can achieve measurement in fairly large viscosity media while keeping a quality factor superior to 90. Measurements performed on oil validate the use of the Lamb system. Oil density is evaluated at 939 kg/m³ and dynamic viscosity at 43 mPa·s which corresponds to our expected values. This shows the possibility of using the sensor outside of the calibration range.

中文翻译：

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压电致动玻璃板，用于液体密度和粘度测量。

本文报告了一种新的液体密度和粘度测量系统，该系统基于由压电陶瓷（PZT）致动器驱动的自由悬挂的矩形振动板。与现有的MEMS谐振器的金标准技术相比，用于这些测量的Lamb模式使我们能够在更大范围内推断密度和粘度。测得的共振频率和品质因数的组合使得能够提取周围液体的密度和粘度。在密度为997至1264 kg / m ^3的甘油水溶液中进行测量时，对系统进行校准粘度范围为1.22至985 mPa·s，与现有的机械谐振器的上限为700 mPa·s相比，动态范围更大。平面外振动模式的品质因数为169（在去离子水（1.22 mPa·s粘度）中获得），对于纯甘油为93（粘度为985 mPa·s）。这款Lamb波谐振传感器可以在相当大的粘度介质中进行测量，同时保持优于90的品质因数。在油上进行的测量验证了Lamb系统的使用。评估油密度为939 kg / m ³，动态粘度为43 mPa·s，这与我们的预期值相对应。这表明可以在校准范围之外使用传感器。