Where should the control film badge be placed?

• A. Worn by the operator
• B. Placed on the patient
• C. Placed away from the primary beam to monitor background exposure
• D. Attached to the lead apron

Answer: (C)

The idea behind a control film badge is to measure ambient background radiation in the room, including scatter and any leakage, not the direct dose from the primary beam. Placing it away from the primary beam ensures the badge records only background exposure, providing a true baseline. If it were placed on the patient, near the beam, or under a lead apron, the reading would misrepresent room background and could be skewed by direct beam exposure or shielding. Keeping the control badge in a location away from the primary beam gives a meaningful comparison to the operator’s personal dosimeter readings and helps verify that overall room safety is within acceptable limits.