Although a wide variety of techniques are available for the determination of PSD in powders, only a relative few appear to be used currently within the cement industry. The choice of technique is probably based on both capability (relative to the material properties of cement) and speed and convenience of analysis. Based on the results of the two ASTM round robin studies, the currently utilized measurement techniques are: laser diffraction, electrical zone sensing (Coulter principle), sedimentation (X-ray sensing), scanning electron microscopy (imaging).
Sieving, though known to be used by the cement industry in the past, was not reported as a technique of choice by any of the round robin participants. The technique most often reported was laser diffraction. In fact, only a handful of participants reported using techniques other than laser diffraction (less than 10%). In this section, we provide a synopsis for each technique as it relates to cement analysis. Greater detail is provided for laser diffraction, since it is the most widely used method for cement powder sizing.