Tandem TOFD Combination Inspection
Tandem TOFD combined inspection is an advanced ultrasonic technique that simultaneously determines surface flaws and depth with precision.
Physical-Chemical Mechanism of Action
The tandem TOFD combination inspection uses two parallel ultrasonic beams emitted from different directions. These beams hit a reflector and return. The difference in travel times of the two beams is measured and allows precise depth determination.
Metallurgical Relevance & Welding Risks
This technique is particularly useful for detecting discontinuities, cracks, and other internal defects in weld areas. It improves inspection safety by simultaneously checking for surface flaws and depth. An error in setting or aligning the beams can lead to inaccurate results, which poses risks to the quality and safety of the welded structure.
Shop Practice & Action Instructions
To perform a tandem TOFD combination inspection, follow these steps:
1. Set up equipment: Make sure the ultrasonic device is properly calibrated and the beams are emitted with the correct alignment.
2. Position the specimen: Position the specimen so that the weld is within the inspection area.
3. Measure travel times: Measure the travel times of the two beams and calculate the depth based on the known sound velocity of the material.
4. Interpret results: Check the results for anomalies and compare them with acceptable standards.