Which of the following is not a method of NDT?

Destructive testing is not considered a method of non-destructive testing (NDT). The primary purpose of NDT is to evaluate the properties, integrity, and quality of materials and components without causing any damage to them. The methods of NDT, such as visual inspection, thermography, and acoustic emission testing, specifically aim to detect flaws, measure characteristics, and assess performance while keeping the item under examination in a usable condition.

In contrast, destructive testing involves subjecting materials to conditions that lead to failure, allowing for an assessment of their mechanical properties but rendering them unusable afterward. This type of testing is often used in situations where understanding the material’s ultimate strength or behavior under load is essential for design or safety requirements, but it does not align with the principles of NDT. Thus, the identification of destructive testing as not being a method of NDT is correct and highlights the key distinction between these two categories of testing.