A solvent used to clean the surface of a test specimen must possess all of the following characteristics except that the cleaner must not be flammable.

A solvent used to clean the surface of a test specimen must possess all of the following characteristics except that the cleaner must not be flammable.

• A. Dissolves oils and greases
• B. Evaporates quickly
• C. Leaves no residue
• D. Must not be flammable

Answer: (D)

The essential idea is choosing a cleaner that actually enables reliable penetrant testing. It must dissolve oils and greases so no oily film blocks the penetrant from entering surface cracks. It should evaporate quickly so the surface dries fast and you’re not left waiting, and it should leave no residue so there’s nothing on the surface that could mask or mimic indications. Whether the cleaner is flammable is not a required property for the cleaning action itself—flammability is a safety consideration, not a functional criterion for cleaning effectiveness. So, nonflammability is not a mandatory characteristic.

The essential idea is choosing a cleaner that actually enables reliable penetrant testing. It must dissolve oils and greases so no oily film blocks the penetrant from entering surface cracks. It should evaporate quickly so the surface dries fast and you’re not left waiting, and it should leave no residue so there’s nothing on the surface that could mask or mimic indications. Whether the cleaner is flammable is not a required property for the cleaning action itself—flammability is a safety consideration, not a functional criterion for cleaning effectiveness. So, nonflammability is not a mandatory characteristic.