Ultrasonic viscosity measurement using the shear-wave reflection coefficient with a novel signal processing technique

Area of Science:

• Materials Science
• Chemical Engineering
• Acoustics

Background:

• Real-time viscosity measurement is crucial for industrial automation.
• Ultrasonic shear wave reflectance is a promising method, but phase measurement is challenging due to temperature dependence.
• Existing magnitude-only methods yield inaccurate viscosity values.

Purpose of the Study:

• To develop an improved ultrasonic method for accurate real-time viscosity measurement.
• To investigate a novel signal processing technique using a frequency band for reflection coefficient calculation.
• To evaluate the method's performance for glycerin and corn syrup-water mixtures.

Main Methods:

• Utilized a mode conversion measurement cell for viscosity measurements.
• Tested glycerin viscosity (15-25°C) and corn syrup-water mixtures (70-100 wt%) at 1 MHz.
• Implemented and analyzed a signal processing technique calculating reflection coefficient magnitude over a frequency band.

Main Results:

• The frequency band technique significantly improved the accuracy of reflection coefficient magnitude measurements.
• Viscosity measurements using the novel method showed reduced errors (up to 14%) compared to conventional rotational viscometry.
• The single-frequency method resulted in substantial viscosity errors (up to 96%).

Conclusions:

• The developed frequency band signal processing technique enhances the accuracy of ultrasonic viscosity measurements.
• This method offers a more reliable alternative to single-frequency ultrasonic approaches for industrial applications.
• The improved accuracy brings ultrasonic viscosity measurements closer to conventional viscometry standards.