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Non Destructive Testing: When is Ultrasonic Testing the Best NDT Testing Method?

calendar Aug. 10, 2020user-iconTXNDT
TXNDT ultrasonic testing on a light pole

Nondestructive testing is an industry responsible for the safe and efficient operation of a number of different fields. As any skilled NDT technician could tell you, different fields require different approaches and testing methods.

While a technician might find visual inspection effective for one job, it may be entirely insufficient for another. Between renewable technology, infrastructure, medical imaging, and every other industry supported by nondestructive testing, NDT technicians must be prepared to use a whole host of testing methods, depending on the demands of each individual job.

Familiarity with each method of testing takes a high level of skill and certification, but the real test of expertise comes from the intuition to know just which method will best serve the component under inspection.

Today on the blog we answer the FAQ: When is ultrasonic testing the best NDT method?

Here’s what you need to know.

Ultrasonic Testing Basics

Ultrasonic testing, as its name suggests, uses the same technology as commonly-used ultrasound machines in the medical field.

Through the use of high frequency sound waves, ultrasonic testing permeates a component to identify discontinuities.

When sound waves travel through a component, sound will reflect back if it hits material with a different acoustical impedance.

As described on our testing disciplines page, “Once received by the sending unit, it will represent as an indication on the screen. Knowing the velocity at which sound travels through a part, along with the time of travel, will allow the technician to determine the distance to the indicated material with a change in acoustic impedance.”

Ultrasonic testing uses a transducer made up of a piezoelectric crystal, converting an electrical current to sound waves--typically compression (longitudinal or straight beam) and shear wave (transverse or angle beam).


Ultrasonic testing (UT) has a number of benefits in comparison to some other NDT testing methods. UT is highly portable and only requires limited access to yield immediate results.

Especially when compared to less precise methods like visual inspection, UT can consistently detect surface and subsurface defects with precision.


When a testing method involves more complicated technology, there are always some mild disadvantages attached to it.

In the case of ultrasonic testing, training is more extensive than other methods and novice technicians are less likely to perform it well.

In the inspection process, it is also more expensive to perform, difficult to use on thin materials, and requires a relatively smooth surface to couple the transducer. Furthermore, part geometry can cause complications in the inspection process and the technician must know the velocity of the part and have a reference to calibrate against for equipment set-up.

Contact TXNDT Today!

Whether it is visual testing, magnetic particle testing, or ultrasonic testing, the best method for inspection must be decided on by a qualified technician, experienced enough to weigh the pros and cons of each method and determine which is the most efficient for the individual job.

At TXNDT, we make sure that each technician we train is fully prepared to enter the workforce. That training includes all of the most important methods, from magnetic particle testing, to liquid penetrant testing, and everything in between.

Since the requirements of an NDT technician can change from job to job, the expert instructors at TXNDT ensure that all prospective technicians are qualified to take on whatever their next job throws at them.

From introductory NDT courses to NDT level 3 certification, we take an active approach to educating all of our students and encourage all prospective technicians to take an active role in their own learning.

If you or your staff are looking for ways to expand your skills and broaden your career opportunities through nondestructive testing courses, consider NDT certification.

But don’t trust just any NDT school. If you’re looking for a top-tier experience, give us a call today at 281-231-0001 or check out our website for more information.