Which method is used to measure loose contamination on surfaces?

Which method is used to measure loose contamination on surfaces?

• A. Direct survey/frisking of the surface
• B. Wiping the surface with a cloth or smear
• C. Breathing rate monitoring
• D. Air sampling only

Answer: (B)

For measuring loose (removable) contamination on surfaces, you want a method that actually collects what can be transferred off the surface. Wiping a defined area with a cloth, filter paper, or smear captures the removable contamination, and the collected material is then counted with a detector to quantify the activity per unit area. This gives a measurement like disintegrations per minute per square centimeter (or Bq/cm²), which reflects how much contamination could be transferred by touch or contact. Direct survey or frisking assesses the surface with a detector but focuses on total surface radiation and may not accurately quantify removable activity per area. Air sampling looks at contaminants in the air, not on surfaces, and breathing rate monitoring is unrelated to surface contamination measurements.

For measuring loose (removable) contamination on surfaces, you want a method that actually collects what can be transferred off the surface. Wiping a defined area with a cloth, filter paper, or smear captures the removable contamination, and the collected material is then counted with a detector to quantify the activity per unit area. This gives a measurement like disintegrations per minute per square centimeter (or Bq/cm²), which reflects how much contamination could be transferred by touch or contact.

Direct survey or frisking assesses the surface with a detector but focuses on total surface radiation and may not accurately quantify removable activity per area. Air sampling looks at contaminants in the air, not on surfaces, and breathing rate monitoring is unrelated to surface contamination measurements.