To calculate the particle size distribution, the DT-1202 is measuring
the sound speed and the attenuation of short ultrasound pulses for a set
of frequencies, typically from 1 to 100 MHz (“transmission pulse
technique” or “tone burst method”). The data will be recorded at
different gaps between ultrasound sender and detector to improve the
accuracy of the signals. Due to the wide frequency range of this unique
technique, very small (< 100 nm) as well as coarse particles
(>> 10 µm) can be measured with a high precision. The variable gap
between sender and detector enables the characterization of diluted
(< 1 vol.-%) and concentrated (up to 50 vol.-%) dispersions. The
WINDOWS-bases software take into account the different
ultrasound-wave-particle interactions as scattering, viscous losses and
thermodynamic effects.
Additionally, the DT-1202 is analyzing the zeta potential of a
dispersion using its electroacoustic probe. Further colloidal parameters
can be calculated like Debye-length, κa-value, Dukhin’sche number and
surface charge density in case of strong non-polar solvents. Due to the
smart design of the probe (pulse-echo method, smooth surface) it can be
easily used both for laboratory experiments and for process-near online
measurements.