Recent developments in pulse reflectometry for tube inspection

Pulse Reflectometry is a noninvasive technique for probing the properties of cavities and materials. In recent years the acoustic version of pulse reflectometry has been applied successfully to inspection of condensers, boilers, preheaters and other heat exchangers,by sending acoustic pulses into the air enclosed within the tubes and analyzing the reflections created by defects on the internal diameter (ID). This method enables detection of defects such as blockages, holes and ID wall loss. Recent developments extending this technique further enable detection of a wider range of defect with higher accuracy. These developments will be presented here, along with tests demonstrating the performance of this technique.