A device for measuring a particle size separating a mass or a number of particles of a system, in particular, in fractions predetermined

摘要

A particle study apparatus which in response to passage of particles in suspension through a sensing device produces electrical pulses which are proportional in amplitude to the size of the respective particles. The apparatus includes a system for ascertaining the particle size above and below which size predetermined fractions of one of the total mass and total number of the particles in suspension are respectively included. If total mass is desired electrical quantities are accumulated in response to each electrical pulse which are proportional to the amplitudes of the electrical pulses. If total number is desired constant electrical quantities are accumulated in response to each electrical pulse. The electrical quantities are designated as being in one of two categories depending upon whether the electrical pulses producing same are greater than or less than a variable threshold. The variable threshold is varied in response to the accumulation of the electrical quantities in order to produce a desired relationship between the quantities such that the accumulated quantities are indicative of the relationship. These quantities are calibrated according to size in order to yield an output representing the dividing size of one of the mass or number of particles in the particulate system.