Abstract: A device for use in determining the characteristics of particles dispersed in a medium is described. The device has a sample cell for holding a sample containing particles dispersed in a medium. A transducer is positioned to emit sound waves into the sample of the sample cell. A mirror surface is positioned for translational movement within the sample cell without changing the level of the sample in the cell, for movement without the use of dynamic o-ring seals, and is positioned to reflect sound waves emitted by the transducer.

Abstract: A device for use in determining the characteristics of particles dispersed in a medium is described. The device has a sample cell for holding a sample containing particles dispersed in a medium. A transducer is positioned to emit sound waves into the sample of the sample cell. A mirror surface is positioned for translational movement within the sample cell without changing the level of the sample in the cell, for movement without the use of dynamic o-ring seals, and is positioned to reflect sound waves emitted by the transducer.

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.

Abstract: This invention is concerned with a method and apparatus for measuring the electro-kinetic properties of a liquid which may be a mixture such as a slurry of particles, or a dispersion of droplets. Electrodes are placed in the liquid and an apparatus is provided for applying an alternating electrical potential to these electrodes. The electric field from this alternating potential acts upon the charged elements in the liquid, resulting in the generation of sound at the frequency of the applied electrical potential. By placing a conventional acoustic transducer in a spaced relationship to the electrodes, the acoustic signal is detected and measured. The amplitude of the acoustical signal will be a function of the electro-kinetic properties of the particles or emulsion droplets in the liquid. In its preferred form, the electrodes that are placed in the liquid have a spacial separation of one-half wave length, or odd integer multiples of half wave length of the sound which they generate.