Internal rotary inspection system

Internal rotary inspection system (IRIS) is an ultrasonic method for the nondestructive testing of pipes and tubes. The IRIS probe is inserted into a tube that is flooded with water, and the probe is pulled out slowly as the data is displayed and recorded. The ultrasonic beam allows detection of metal loss from the inside and outside of the tube wall.

Principle of operation

The IRIS probe consists of a rotating mirror that directs the ultrasonic beam into the tube wall. The mirror is driven by a small turbine that is rotated by the pressure of water being pumped in. As the probe is pulled the spinning motion of the mirror results in a helical scan path.

One of the key settings in the procedure is to ensure that the ultrasonic pulse initiates in the very focus point at the center of the tube or pipe. An off-center pulse will show a distorted image of the tube due to the difference in the sound path for either side of the tube wall. For that reason there are centering devices that help the operator to keep the turbine centered at all times.

The transducer utilized for the inspection has to be high frequency, enough to bounce back at both inner wall and outer wall. Frequency range typically used range from 10-25 MHz in a piezoelectric transducer.

Features

Sources

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.