Page 772 - Radiation Safety

Calibration and Quality Control

• All dosimeter are characterized by the manufacturer at the time of

production.

• It is compulsory that the dosimeter be calibrated periodically as stipulated

by the appropriate authority.

• Purpose of the calibration:

• Film dosimeter and TL dosimeter are not absolute dosimeter and do not

provide direct reading.

• Film sensitivity decreases with storage time due to environmental exposure
therefore recalibration is required for every six months.

• Sensitivity of TLD may decreases with the number of use, it may due to the
mishandling of the TLD material (TLD chip) –surface scratch, deterioration of
teflon (TLD binder) in TLD card. Recalibration is recommended for every 6

months

• to adjust or determine the response or reading of a dosimeter relative to a
standard or to a series of conventionally true values. (pocket dosimeter)