Abstract
In this paper, we compared the effects of particle agglomeration and different operating procedures on the results from two measuring instruments, i. e. , coulter counter and micron photo sizer. If the powder is made up of loosely agglomerated particles, such as CaCO//3, the use of ultrasonic disperser will affect its results significantly. On the other hand, if the sample has been treated at high temperature, such as alpha -Al//2O//3, its effect will then be lesser. In general, the reproducibility of micron photo sizer is not as good as that of coulter counter and it is limited by the stability of its light source, the difficulty to control the mixing state of the powder and the settling medium and unavoidable deviation from free settling process. Yet, by choosing a suitable settling medium to lessen some of the above problems, we can still obtain comparable results from micron photo sizer to those from the coulter counter.