The Resonance Acoustic Method (RAM) is a long-standing nondestructive test (NDT) that measures the structural responses of a part. These responses are a set of unique and measurable natural frequency (resonance) data.

Resonant inspection (RI), the general classification of Resonant Acoustic Method (RAM) nondestructive testing, is commonly used for 100% quality assurance testing of ductile iron cast, powder metal (PM), and metal injection molded (MIM) components, providing a volumetric whole body approach that detects both external and internal structural flaws and anomalies.