What is the difference between a smear (wipe) test and a survey meter reading?

What is the difference between a smear (wipe) test and a survey meter reading?

• A. A smear test measures ambient radiation fields; a survey meter measures surface contamination
• B. A smear test measures removable surface contamination; a survey meter measures ambient radiation fields
• C. Both measure identical quantities
• D. A smear test measures dose in tissue; a survey meter measures shielding integrity

Answer: (B)

The key idea here is the difference between measuring contamination on a surface versus measuring the radiation present in the environment. A smear (wipe) test collects a known amount of surface material by wiping a defined area and then analyzes the collected material to determine how much radioactive contamination is removable. It tells you how much contamination could potentially be transferred off the surface, which is a contamination-control and transfer-risk metric, not a dose or exposure measurement in tissue. A survey meter, on the other hand, measures the ambient radiation field at a location—essentially the dose or exposure rate in the surroundings. It reflects how much radiation is currently present in the environment, not how much contamination is on a surface or how easily it could be transferred. So, smear tests quantify removable surface contamination, while survey meters quantify ambient radiation fields. The two assess different things, which is why they’re not interchangeable.

The key idea here is the difference between measuring contamination on a surface versus measuring the radiation present in the environment. A smear (wipe) test collects a known amount of surface material by wiping a defined area and then analyzes the collected material to determine how much radioactive contamination is removable. It tells you how much contamination could potentially be transferred off the surface, which is a contamination-control and transfer-risk metric, not a dose or exposure measurement in tissue.

A survey meter, on the other hand, measures the ambient radiation field at a location—essentially the dose or exposure rate in the surroundings. It reflects how much radiation is currently present in the environment, not how much contamination is on a surface or how easily it could be transferred.

So, smear tests quantify removable surface contamination, while survey meters quantify ambient radiation fields. The two assess different things, which is why they’re not interchangeable.