Which method is used to measure fixed contamination on surfaces?

Which method is used to measure fixed contamination on surfaces?

• A. Direct survey/frisking of the surface
• B. Contamination which cannot be removed or transferred easily
• C. Wiping the surface with a cloth or smear
• D. Directing the HEPA discharge over contaminated surfaces

Answer: (A)

Direct survey or frisking the surface is used to measure fixed contamination. By scanning the area with a handheld radiation detector, you assess the radiation from contaminants that are bonded to the surface without removing the surface itself. Fixed contamination won’t come off easily, so a wipe test wouldn’t reliably quantify it; wipe tests are designed to measure removable contamination, not what’s fixed to the surface. Decontamination methods like using HEPA discharge are about removing contamination, not measuring it.

Direct survey or frisking the surface is used to measure fixed contamination. By scanning the area with a handheld radiation detector, you assess the radiation from contaminants that are bonded to the surface without removing the surface itself. Fixed contamination won’t come off easily, so a wipe test wouldn’t reliably quantify it; wipe tests are designed to measure removable contamination, not what’s fixed to the surface. Decontamination methods like using HEPA discharge are about removing contamination, not measuring it.