What type of inspection identifies structural integrity without damaging the sling?

The correct choice is the proof test. This type of inspection involves subjecting the sling to a predetermined load to demonstrate that it can safely hold that load without being permanently deformed or damaged. The proof test is designed to confirm the strength and performance of the sling under realistic conditions, ensuring that it meets safety standards while preserving its structural integrity.

Conducting a proof test helps validate the sling’s load-bearing capacity, and it is typically done without causing any harm to the sling itself. This method is crucial for ensuring safety in operations involving heavy lifting, as it provides confidence that the sling can perform as expected under operational conditions.

In contrast, other inspection methods, such as destructive testing, are not suitable for assessing the structural integrity of a sling without causing damage, as they intentionally compromise the item being tested. Visual inspections are vital for identifying obvious defects or wear but do not provide a comprehensive assessment of the sling's internal integrity. X-ray inspections can reveal hidden flaws but usually involve more complex procedures and are not standard for slings in typical rigging applications.