ASNT Industrial Radiography Radiation Safety Practice Test

Which dosimeter type is least affected by moisture?

1. Film badges

2. Electronic dosimeters

3. TLDs

4. Personal ionization chambers

The correct answer is: TLDs

Thermoluminescent dosimeters (TLDs) are the type of dosimeter least affected by moisture because they operate based on the principle of storing energy from ionizing radiation and releasing it as light when heated. The materials used in TLDs, such as lithium fluoride, are inherently stable in various environmental conditions, including humidity. Unlike film badges, which can be significantly compromised by moisture, resulting in fogging or inaccurate readings, TLDs maintain their sensitivity and accuracy regardless of the moisture levels in the environment. This stability makes TLDs particularly suitable for use in environments where exposure to moisture is a concern, ensuring that radiation dose measurements remain reliable and effective. In contrast, while electronic dosimeters and ionization chambers might also be somewhat resilient, they may still be influenced by external factors to a greater extent than TLDs.