This project presents and discusses the development and functioning of a test bench that simulates the injection system of abrasive spheres of a heat exchanger tube cleaning system used in hydro generator cooling of the Fontes Novas power plant, property of the Energia Light Serviços de Eletricidade SA dealership. An optoelectronic system has been developed to automatically count the cleaning spheres, ensuring that all spheres are collected after each cleaning cycle. Using a photodiode-photo detector pair, in the infrared band, a automated system was developed that counts the abrasive spheres immersed in the flow and measures individual velocity of each sphere. This project complements the development of the sphere injector system, developed in Velfe Hollandino de Oliveira Junior s master dissertation (defended in 2015), which didn t contain these features.