PURPOSE: To measure dispersibility on the condition where the slip speed of a liquid sample is zero by holding the liquid sample in a sample holding container, supporting it on a base movably, and measuring and displaying the dispersibility of particles while moving the container.

CONSTITUTION: The necessary sample is charged in the sample holding transparent container 1, which is supported on a moving stage 9; and this stage 9 is supported movably on the base 10 and also put in reciprocal motion by the pulse motor 8 of a motion control part 4. Light from a light source part 2, on the other hand, illuminates sample particles in the container through an optical fiber 7 top generate a scattered light signal, shade signal, or reflected signal. This signal is inputted to a photoelectric conversion part 3 through the optical fiber 7. The signal is converted by the photoelectric conversion part 3 into an electric signal, which separated by a signal processing part 5 into a DC part and an irregular variation part and converted into the function signal of the irregular variation component, e.g. a square mean signal or proportion signal of the square mean value and a DC component. This function signal is display or recorded automatically by a signal display part 6.