Years of Particle Size Conferences

DEPARTMENT OF CHEMICAL ENGINEERING, TECHNICAL UNIVERSITY, P.O. BOX 5045, DELFT, 2600 GA, THE NETHERLANDS 

It is almost precisely twenty five years since the first of these conferences, organised then by the Particle Size Sub-Committee of the Society of Analytical Chemistry which has now grown in to the Particle Size Characterisation Group of the Analytical Division of the Royal Society of Chemistry. The sub-committee had recently completed a review of 74 different methods of particle size analysis and these efforts were the inspiration both for the first conference and for the formation of the permanent subject group. This is the seventh conference in the series and it is entirely appropriate that it should be held in the same place, at Loughborough University. The proceedings of each of the conferences is permanently documented by a bound book of conference proceedings. Several authors feature in all the seven conferences. 

The closing address at the first conference was given by Professor Harold Heywood [1], an address which was based on many years of experience and which could be given, almost without modification, at the end of this conference and stili be entirely appropriate. Thus, some truths do not change and although they must be learnt anew by each succeeding generation, they remain essentially the same. 

The developments which he foresaw have largely occurred over the intervening twenty five years but it may be that now those basic messages have even more practical importance and that the rate of development grows exponentially. In this paper, my intention is to re-state some of the message of Heywood and to illustrate it in the circumstances of today. 

The first quotation I would like to take concerns 

---

Several monographs that describe the theory and experimental requirements for good measurements are available (1-5). Hundreds of literature citations are included in these sources. Every year conferences are devoted to the subject of QELS and PCS. Although the technique is relatively new to particle size analysts, most of the advantages and disadvantages are well-known. 

---