The most efficient and effective NDT methods

14 Sep 2020

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 Sep 14, 2020
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In this recent round of blogs, we’ve been going all out to demystify the mysteries behind non-destructive testing and evaluation. In this blog, we’ll be homing in on three of the most effective NDT methods to give you a better idea of why we think they’re the methods you should consider above all else.

The most effective NDT methods

There are several NDT methods you can make use of to test your materials, we cover them in some depth in this blog[LM1] . The NDT methods we’ve selected for this blog though are said to be the most effective methods of modern NDT: Ultrasonic testing and leak testing.

Ultrasonic Testing

Also known as Acoustic Emission Testing, this effective NDT method relies on high-frequency waves of ultrasound to detect flaws such as cracks and deformities, as well as to monitor the structural health of your item. This method is most effective for larger objects such as gas/chemical tanks and large structural components.

Ultrasonic testing works by inducing high-frequency sound waves into solid objects that then travel throughout the object at ultrasonic speeds. The journey into the sound waves take, is affected by irregularities such as density variations, cracks, voids, honeycombs, or foreign objects.

Depending on the equipment used, as well as the application you’re using this NDT for, waves can be collected as they reflect back or pass through the material being scanned. As they’re reflected, these waves will translate into readings that testers can use to detect the flaws with certainty. If you’d like to learn more about ultrasonic testing, don’t hesitate to get in touch with us!

Leak Testing

Leak testing is one of the oldest and most effective NDT methods available and can be broken down into four categories: bubble leak testing, pressure change testing, halogen diode testing and mass spectrometer testing.

Bubble Leak Testing

Bubble leak testing makes use of a tank of liquid (or a soap solution for larger parts) to detect gas, usually air, leaking from the test piece in the form of bubbles. This testing method is generally used for smaller structures and components.

Pressure Change Testing

Pressure testing is only used in closed systems (such as a gas tank) or vacuums to monitor the component being tested and detect any and all leaks in the component.

Halogen Diode Testing

This testing method uses a similar procedure as with pressure testing but differs in that a halogen-based tracer gas and air are mixed together in a halogen diode unit. The apparatus in then used to detect the smallest of leaks in the test piece.

Mass Spectrometer Testing

Mass spectrometer testing makes use of helium (or a mix of helium and air) inside a test chamber that is equipped with a piece of detection equipment called a ‘sniffer’ that can detect any changes in the air sample, changes that would indicate the presence of a leak.

At the end of the day, no matter how effective these NDT methods are, the practice of non-destructive testing is an all rounded one that often requires the use of more than one NDT method. This is what we at Ultra Scan specialise in, contact us today to learn more!