Time of Flight Diffraction (TOFD) is a sensitive and accurate method for Non-Destructive Testing (NDT) of welds for defects. The SGS NDT Training and Examination Center hosted its first Time of Flight Diffraction (TOFD) Level 2 SNT training course in Shanghai, China. Candidates from all over the world were present, including those from New Zealand, Malaysia, Canada, China and Belgium.

The TOFD course was conducted in cooperation with the SGS Global NDT – Special Examinations Center in Netherlands. Norbert Trimborn, NDT specialist from Holland performed the course, providing his international expertize on this topic.

This was the first of many TOFD courses to be held in the future and SGS hopes to offer a Personnel Certification in Non-Destructive Testing (PCN) TOFD course very soon.

Reacting to an increasing demand for qualified NDT inspectors, SGS established a Non-Destructive Testing Training and Examination Center in Shanghai, China. This SGS Training and Examination Center offers not only training but certification and examination opportunities for Non-Destructive Testing and Inspection in accordance with worldwide standards.

Time of Flight Diffraction was invented in the UK in the 1970s for the nuclear industry and is considered one of the fastest NDT methods to characterize welds. TOFD is a fully-computerized system which scans and evaluates discontinuities in terms of height, length, and position. This NDT method is based on the diffraction of ultrasonic waves and differs from the traditional pulse echo technique as it monitors diffracted signals at the edge of defects which are directly related to the true position and size of the defect. The Probability of Detection (POD) increases greatly (up to 90%) for flat or spherical defects compared to traditional techniques.

SGS also provides a fully integrated service pack for its clients, combining Non-Destructive Testing Services, Inspection and Asset Integrity Management through its worldwide NDT network in over 30 countries.


NDT Training & Examination Center

2F, Building 8,
69 Kangqiao Industrial Park,
1159 East Kangqiao Road,
Pudong District,
Shanghai 201319, P.R.C.
t: +86 (0)21 6818 3905

About SGS

The SGS Group is the global leader and innovator in inspection, verification, testing and certification services. Founded in 1878, SGS is recognized as the global benchmark in quality and integrity. With more than 55,000 employees, SGS operates a network of over 1,000 offices and laboratories around the world.