Abstract: A colloid analyzer is provided employing a relatively low frequency, low power, continuous "acoustic" wave signal propagated in the direction of spaced electrodes mounted adjacent to the side wall of a chamber or vessel containing a colloid sample. The chamber further comprises a series of probes for respectively sensing the pH, temperature, and conductivity of the sample(s) being analyzed. A piezoelectric transmitter generates the acoustic drive signal. The spaced electrodes in conjunction with an electronic signal processing circuit serves as a receiver and generates an output signal relating to the magnitude and polarity of the zeta potential of the particles being "acoustically" excited by the drive signal. A computer responsive to the signal processing circuit's output signals and/or the vessel probes' output signals alternately develop a graphical output relating to zeta potential, and/or one relating to the surface charge density of the analyzed colloid for given levels of titration.