Industrial Ultrasonic Testing Equipment (UT)

Ultrasonic Testing (UT) is a form of non-destructive testing (NDT) that employs high-frequency sound waves for the purpose of characterizing the thickness or internal structure of a given sample. The frequencies used for UT are typically in the range of 500 kHz to 20 Mhz.

As a non-destructive testing method, ultrasonic testing is ideally suited to the detection of flaws, defects, and welded seams where destruction of the target sample is not an option.

In addition to detecting flaws in production samples, periodic UT inspections are also perfect for checking for corrosion in existing equipment, such as pipelines, and is therefore an indispensable part of any predictive maintenance program.

Ultrasonic Testing (UT) is ideally suited for the inspection of material structures such as metals, ceramics, plastics, and composites.

While denser materials up to and including concrete can be successfully inspected, the output resolution is usually less-defined.

Highly porous biological materials such as wood and paper do not react well to ultrasonic testing.

Yes, ultrasonic testing (UT) can be used on stainless steel. UT is a non-destructive testing method that uses high-frequency sound waves to detect flaws or measure thickness in materials. While stainless steel can present some challenges due to its grain structure, UT is still an effective method when performed correctly, often using specific techniques to address potential difficulties with signal scattering.

Ultrasonic testing (UT) works by sending high-frequency sound waves into a material using a transducer. These sound waves travel through the material and reflect back to the transducer when they encounter a boundary or defect, such as cracks or voids. The reflected waves are then recorded and analyzed to determine the location, size, and nature of the flaw. By interpreting the time it takes for the waves to return and the strength of the reflection, inspectors can assess the material's integrity without causing any damage.

Selecting the right angle probe in ultrasonic testing depends on several factors, including the material being inspected, the type of defect you're trying to detect, and the geometry of the part. Here's a basic guide to selecting an angle probe:

• Material Type: Different materials will affect sound wave transmission. Choose a probe with a frequency that matches the acoustic properties of the material.
• Defect Location and Type: For surface or near-surface flaws, a shallower angle (e.g., 45°) is often used. For deeper defects, higher angles (e.g., 60° or 70°) may be more effective.
• Part Geometry: Complex geometries may require specific angles to ensure proper coverage of the inspection area. For example, 45° is commonly used for weld inspections, while other angles might be required for specific shapes.
• Code and Standards: Follow industry-specific standards (e.g., AWS, ASME) which may dictate specific probe angles for particular inspection types.

Proper probe selection ensures accurate detection of defects and reliable test results.

To test an ultrasonic transducer, follow these steps:

• Visual Inspection: Check the transducer for any visible signs of damage, such as cracks or wear on the surface. Ensure that the cables and connectors are intact.
• Impedance Testing: Use an impedance analyzer to measure the electrical impedance of the transducer. Compare the result with the manufacturer's specifications to ensure it falls within the acceptable range.
• Pulse-Echo Test: Connect the transducer to an ultrasonic testing device and perform a pulse-echo test. Place the transducer on a known calibration block and observe the reflected signal on the screen. Ensure that the signal is clear and has the correct amplitude and timing.
• Frequency Check: Verify that the transducer is operating at the correct frequency using an oscilloscope or frequency analyzer. This ensures the transducer is emitting sound waves at the specified frequency.
• Signal Strength and Consistency: Check the strength and consistency of the signals produced by the transducer over multiple tests. A weak or inconsistent signal may indicate that the transducer is malfunctioning.

These tests help ensure that the ultrasonic transducer is functioning properly and providing accurate results.

The three main types of ultrasonic inspection methods are:

• Pulse-Echo Testing: This method sends a pulse of sound waves into the material, and the waves reflect back when they hit a flaw or boundary. The time it takes for the echo to return is used to determine the location and size of defects. It's widely used for detecting internal flaws and measuring thickness.
• Through-Transmission Testing: In this method, two transducers are used—one on each side of the material. One transducer sends sound waves through the material, while the other receives them on the opposite side. A reduction in signal strength indicates the presence of a flaw. This method is effective for detecting large defects.
• Phased Array Ultrasonic Testing (PAUT): This advanced technique uses multiple transducer elements that can be controlled to steer, focus, and scan sound beams across a material. PAUT provides detailed, real-time images of the internal structure, allowing for more accurate detection and sizing of defects.

These methods are used based on the specific inspection requirements and material properties.