This book documents the proceedings of the Symposium on Particles in Fluids: Detection, Characterization and Control held as a part of the 18th Fine Particle Society meeting in Boston, August 3-7, 1987. This was the Premier symposium on this topic and the response was so good that we have decided to organize it on a biennial basis and the second symposium will be held under the rubric Particles in Gases and Liquids: Detection, Characterization and Control at the 20th Fine Particle Society meeting in Boston, August 22-26, 1989. In the modern manufacture of sophisticated and sensitive microelectronic components and other precision parts, there has been a great deal of concern about yield losses due to micrometer- and submicrometer-sized particles. These particles can originate from a number of sources including fluids, i. e. , gases and liquids used in the manufacturing process. So the detection, characterization and control or removal of these undesirable particles is of cardinal importance and this symposium was conceived and organized with this in mind. The purposes of this symposium were to bring together those actively involved in all aspects of particles in fluids, to provide a forum for discussion of the latest techniques for the detection, characterization and control of particles, and to highlight areas which needed intensified R&D efforts. The printed program contained a total of 46 papers and a variety of topics dealing with various ramifications of particles in fluids were presented.