Non-Destructive Testing Methods: Internal Rotary Inspection System (IRIS)

Similar to eddy current testing, this test method uses an internal probe to inspect heat exchangertubes. But unlike eddy current, ultrasonic inspection is the basis of the method. The IRIS probe head uses an ultrasonic transducer and a spinning mirror to inspect the tube walls. The tube is flooded with water while testing, to provide a couplant for the ultrasonic beam. As the probe is manually pulled through the tube, the rotating mirror results in a helical scan path and the results are recorded on a computer. This method accurately measures tube thickness or any wall loss at the ID or OD and can be used on any tubing material (ferrous and non-ferrous). Limitations of this method include the high cost of equipment and operator training, and the requirements for clean tubes and constant supply of water. Although this method is excellent at measuring corrosion and wall loss, it may fail to find certain cracks or pinholes. Please contact us if you are interested in learning more about this testing method for your next project.