An ultrasonic inspection is a nondestructive form of inspection which is designed to gather information about the properties of a material through the use of ultrasound. This technique is most commonly used on metals, because they are ideal substances for evaluation with ultrasound, although other materials may be inspected in this way as well. This task can be performed by a company which specializes in ultrasonic inspection, or by a worker who has been trained in how to perform this technique, as may be done on a construction site where workers want to monitor progress.
In an ultrasonic inspection, a transducer is used to bombard the object of interest with ultrasound waves. A couplant such as water or oil is used to facilitate the movement of the ultrasound waves. Then, the waves are read on their return to gather data about the material. The movement of the waves can be used to gather basic information about thickness, and it can also reveal flaws such as cracks and bubbles which may not be visible.
One common use for ultrasonic inspection is in welding inspections. Ultrasonic welding inspections are used to test welds without damaging them, to confirm that the welds are sound. If a flaw is revealed, the issue can be addressed. Ultrasonic inspection is also used to inspect pipes and other structures to see if something inside has gone wrong. For example, an ultrasonic inspection of plumbing may reveal extensive corrosion inside the pipes which has weakened their walls.
The nondestructive nature of this materials testing technique is highly beneficial. Often, people want to be able to inspect something to confirm that it is safe, but they do not want to damage it in the process. With ultrasonic inspection, safety concerns can be addressed without compromising the integrity of an object or project. This also means that testing is easier and more likely to be completed, which increases safety.
Ultrasonic inspection equipment is quite varied, running a gamut from handheld units which can be used by welders to quickly inspect an area of interest to large units which require objects to be submerged in a bath of couplant for inspection. Such equipment tends to be costly, and must be maintained properly to ensure that it will work effectively when it is called upon. Maintenance can include periodic recalibration and servicing at the manufacturer's facilities, including tests of known materials which confirm that the unit is working.