Which inspection tool is most commonly used to detect internal flaws in the container walls?

Ultrasonic testing equipment is the most commonly used tool for detecting internal flaws in container walls, particularly in tanks that store liquids like LP gas. This method utilizes high-frequency sound waves that are transmitted into the material. When these sound waves encounter a flaw or an imperfection, they are reflected back to the device, allowing for the detection of internal discrepancies such as cracks, voids, or corrosion. The advantages of ultrasonic testing lie in its ability to provide precise and reliable results without the need to disassemble the container or remove it from service.

In contrast, other tools mentioned, such as a magnifying glass, are primarily for surface inspections and cannot adequately assess internal issues. A thermal camera detects temperature variations on surface areas and is useful for identifying heat loss or insulation failures, but it cannot reveal internal structural flaws. A moisture meter measures moisture levels in materials and does not relate to the integrity of container walls concerning cracks or other internal defects. Thus, ultrasonic testing stands out as the appropriate choice for ensuring the safety and integrity of LP gas containers through thorough internal assessments.