What is necessary during the immersion method?

• A. No agitation
• B. Agitation to continuously expose fresh penetrant and break apart penetrant into smaller easier to remove drops
• C. Heating to raise temperature
• D. Ventilation

Answer: (B)

Agitation during immersion is essential because it keeps fresh penetrant at the surface and continually exposes new penetrant to the defect surfaces. It also breaks the penetrant into smaller droplets, which makes it easier to remove excess penetrant and reduces pooling. This combination improves penetrant access to tight defects and yields clearer indications after the developer is applied. Heating or ventilation aren’t required parts of the immersion step, and leaving the bath still would risk stagnant penetrant, uneven penetration, and larger pools that waste penetrant and obscure indications.