Acoustic attenuation spectroscopy for process control of dispersed systems

Acoustic Attenuation Spectroscopy (AAS) is a technique for the measurement of Particle Size Distribution (PSD) of concentrated colloids – in most cases without the need for sample dilution, i.e., at process conditions. While successful in the laboratory, AAS has not been widely employed for Process Control purposes. This paper describes a new flow-through (Process Online) measurement approach that can make AAS into a Process Control tool for industrial production settings, in particular for PSD measurement and control. This approach basically consists of splitting ultrasonic sound waves by using stepped reflectors and/or transducer delay rods which provide multiple measurement gaps without the use of moving parts.