Drift tests on cooling towers are performed by experts using specifically designed equipment to capture a representative sample of water droplets as they exit the cooling tower. This measurement could be done for diagnostic, contractual acceptance, or regulatory compliance purposes. CleanAir’s experts were part of the initial CTI drift emission test code-writing committee in the 1990s and have chaired the committee for the past 20 years. In fact, we developed the technology used for most drift testing. This video gives an overview of what a drift test is, when it’s needed, and why it’s performed.