The installation of sprinklers can result in substantial reductions in insurance premiums and so insurance companies are becoming increasingly interested in their proper installation and function. For example, the British Automatic Fire Sprinkler Association has abundant evidence about the effectiveness of their members’ technology in reducing loss of life and property in office, residential, retail, storage, public venue buildings and in special sites such as ships, control rooms and hospitals.The proper functioning of fire sprinkler systems can be catastrophically undermined by corrosion. The water in the system pipes is stagnant and, if inhibitors are inactive, then this can give rise to microbiological induced corrosion (MIC), which leads to leaks. This corrosion is localised and is not evident in close visual inspection until the leak starts. Moreover the pipes are often enclosed and difficult to access for close viewing. MIC may occur in both dry and wet sprinkler systems.Long range ultrasonic testing (LRUT) has been developed for screening long lengths of pipe (up to 100m from one test location) for corrosion, especially in otherwise inaccessible areas. It has been used to a limited extent on the feeder pipes and risers in sprinkler systems. However, the pipe lengths are too short (typically <5m) and the defects too small in comparison with the ultrasound wavelengths for current LRUT systems. Moreover the numerous features such as pipe elbows and branches, makes interpretation of ultrasound echo-signals difficult.SprinkTest aims to inspect automatic fire sprinkler systems by developing a medium range ultrasonic test (MRUT) system, using higher frequency ultrasound (100KHz -500KHz), smaller flexible transducers to gain access to confined spaces, lower power electronics to allow hand-held portability and sophisticated software to process signals and extract information from the numerous guided ultrasonic waves present at the higher frequencies.