Coincidence Corrections for Particle Size Determinations with the Coulter Counter

A new mathematical treatment has been given for coincidence corrections necessary in determining particle size distributions by means of a Coulter counter. The coincidence phenomenon has been divided into ``horizontal'' and ``vertical'' interactions, of which the latter is believed to predominate. Expressions are developed relating the observed count, the real number of particles, the mean diameter, and the standard deviation of a distribution. The resulting equations are rather complex, and although manual solution is not impossible, an electronic digital computer would decrease the time required.