Tandem Technique
Tandem technique is an ultrasonic method with separate transmitter and receiver heads that detects vertically oriented discontinuities in workpieces. It improves detection of deep-lying inhomogeneities.
Physical-Chemical Mechanism of Action
The tandem technique uses two separate ultrasound heads: one transmitter and one receiver. The transmitter sends ultrasonic waves into the workpiece, while the receiver detects the returning waves. This allows precise detection of separations and inhomogeneities, since the waves propagate perpendicular to the workpiece surface.
Metallurgical Relevance & Welding Risks
This technique is especially useful for inspecting weld areas and other complex material structures. It can detect deep, mirror-like inhomogeneities and separations that other ultrasonic methods might miss. Misuse or incorrect application can lead to inaccurate results, which in turn leads to missed defects.
Shop Practice & Action Instructions
To use the tandem technique effectively, follow these steps:
1. Equipment: Use separate transmit and receive probes.
2. Settings: Optimize ultrasonic frequency and amplitude for the specific workpiece.
3. Procedure: Move the probes along the surface to be inspected while continuously monitoring the feedback.
4. Evaluation: Carefully analyze the results and compare them with the specific requirements of the workpiece.