What is the average accuracy of a thermoluminescent dosimeter?

• A. +/- 1%
• B. +/- 9%
• C. +/- 25%
• D. +/- 40%

Answer: (B)

Accuracy in this context means how close the reported dose from a thermoluminescent dosimeter is to the true delivered dose. TLDs work by storing energy in a crystal and then releasing light when heated; the light readout is calibrated against known doses, but several real-world factors affect how close that readout is to the actual dose. These factors include how well the system is calibrated, the crystal’s energy response, the precision and stability of the reader, fading of the stored signal if there’s a delay before readout, and batch-to-batch variations in the crystals. When these elements are managed in routine practice, the overall error tends to fall in a range around ten percent. On average, measurements are typically within about ±9% of the true dose, which is why this option is considered the best choice. Very tight figures like ±1% aren’t realistic for standard TLD systems, while much larger values (±25% or ±40%) would indicate a loss of trustworthiness in the measurements.