2003-(II)-Ultrasonic techniques - The Resonator
Article Index
Ultrasonic instruments:
The ultrasonic cell consists of two piezoelectric transducers arranged parallel to each other. One of these disc-shaped transducers acts as the transmitter, the other one as receiver. The surfaces of the used transducers are coaxially plated with electrodes (chrom/gold). The soundwave is induced by the inverse piezoelectric effect.
In principle two kinds of ultrasonics techniques were used in present project; the resonator method and the pulse transmission method. The principle of the resonator method is based on folding the acoustic path via multiple reflections in order to obtain a resolvable amplitude decay at lower frequencies. With the help of pulse methods it is possible to make measurements of the exponential amplitude decay versus distance of propagating waves, which propagate through the liquid. Standing and the traveling wave methods overlap in a wide range and can be used to check the consistency of measured ultrasonic spectra.