ASNT Radiographic Testing Practice Test 2026 – Comprehensive All-in-One Guide for Exam Success!

A very light irregularly-shaped small image in a pipe weld on a radiograph typically indicates tungsten inclusion. This phenomenon occurs when tungsten from the electrode contaminates the weld bead during the welding process. The irregular shape corresponds to the unique nature of the tungsten inclusion, which can appear lighter on the radiograph due to its density compared to the surrounding material.

In radiographic testing, tungsten has a higher atomic number than the weld metal around it, which can result in a lighter image on the film because the x-rays are attenuated less by the tungsten. This creates a visual anomaly that stands out against the weld image, helping inspectors identify potential defects.

In contrast, weld porosity would generally show as darker spots on the radiograph, assuming they are gas pockets trapped in the weld metal, rather than irregular shapes. Surface contamination could result in a less distinct image, but typically would not present as an irregularly shaped inclusion. Inadequate exposure might produce an overall underexposed radiograph but wouldn't account for a specific light, irregular shape, as seen with tungsten inclusion.