COMPARISON OF PARTICLE SIZE DISTRIBUTIONS OF MONODISPERSE PARTICLES FROM 0.8 TO 3.5 MU IN DIAMETER USING A COULTER COUNTER AND ELECTRON MICROSCOPY

Analysis of particle size distributions of four monodisperse sols containing particles in the range of diameter 0.8 to 3.5 μ, using the Coulter Counter revealed, when compared with those obtained by electron microscopy, two basic anomalies. The first, an apparent build up in particle concentration to lower particle sizes, was found to be characteristic of the particular 30 μ orifice in use at the time. The second, a positive skew in the distribution to larger particle sizes, which may be the result of coincidence effects. The need for thorough checking of the behaviour of an orifice tube before use with heterodisperse systems is stressed. © 1968 Dr. Dietrich Steinkopff Verlag.