ULTRASONICS IN CHEMICAL-ANALYSIS

Ultrasonic techniques are attractive for chemical analysis for a number of reasons. In particular, they can often be used non-invasively, the energy levels are low, no radioactivity is involved, 'moving parts' are not usually required, the response is rapid and a range of mutually compatible techniques is available. Ultrasonic transmitters and receivers are readily available commercially and, using them, sensors can be constructed for on-line analytical applications for use in the laboratory. In addition, complete ultrasonic analytical systems are already on the market. The principal ultrasonic parameters which can be measured are the velocity, attenuation and scattering of ultrasound and the acoustic impedance of the medium through which it is travelling. From these it is possible to determine chemical identity, the concentrations (or density) of solutions, mixtures and dispersions, and the particle size of dispersed phases.