The often difficult challenge of selecting the right mixer for specific process applications is made easier when thorough testing is possible. At the Test & Development Center of Charles Ross & Son Company, a major leading manufacturer of mixing equipment, their Malvern Mastersizer particle size analyser is one of the analytical instruments used by customers during process simulations. Provided as complimentary service, it is used availed by customers from a wide range of industries and from around the world. Working at the test centre with their own raw materials, customers simulate their processes using Ross mixing, blending and dispersion systems. The Mastersizer is applied during the course of process optimisation and verification, as an aid to selecting the proper mixing equipment and correct process conditions.