A suspension is a mixture in which solid particles (organic or inorganic in nature) are dispersed in a liquid medium, but not dissolved. Suspensions are usually opaque or cloudy and can settle over time due to gravity. They have a broad range of applications and are present in various industrial processes, such as chemical, pharmaceutical, food and beverage, and environmental industries. During the production of pharmaceutical formulations for example, professionals may measure particle concentration to assess whether particles have aggregated or formed larger clusters to optimize the process and ensure product quality.