Which piece of laboratory equipment would be effective for serial number recovery?

• A. X-ray diffraction
• B. Magnetic resonance
• C. Ultrasonic cavitation
• D. Ultrasonic cavation

Answer: (D)

Serial number recovery hinges on removing the grime, paint, or corrosion that often hides engravings on metal surfaces. Ultrasonic cavitation uses high-frequency sound waves in a liquid to create countless tiny bubbles that collapse violently, generating microjets and shock waves that scrub away surface contaminants. This action is especially effective in reaching recessed areas and worn engravings without damaging the underlying metal, making a faint or obscured serial number visible again. The other options aren’t suited for this purpose: X-ray diffraction reveals information about a material’s crystal structure rather than markings, magnetic resonance isn’t a standard method for exposing surface engravings, and while ultrasonic cleaning (the cavitation process) is the tool that makes the number readable, the term refers to the mechanism by which the contamination is removed.