evaluation of effective sources in uncertainty measurements of personal dosimetry by a harshaw tld system

background: the accurate results of the individual doses in personal dosimety which are reported by the service providers in personal dosimetry are very important. there are national / international criteria for acceptable dosimetry system performance. objective: in this research, the sources of uncertainties are identified, measured and calculated in a personal dosimetry system by tld. method: these sources are included; inhomogeneity of tlds sensitivity, variabil- ity of tld readings due to limited sensitivity and background, energy dependence, directional dependence, non-linearity of the response, fading, dependent on ambient temperature / humidity and calibration errors, which may affect on the dose responses. some parameters which influence on the above sources of uncertainty are studied for harshaw tld-100 cards dosimeters as well as the hot gas harshaw 6600 tld reader system. results: the individual uncertainties of each sources was measured less than 6.7% in 68% confidence level. the total uncertainty was calculated 17.5% with 95% confi- dence level. conclusion: the tld-100 personal dosimeters as well as the harshaw tld-100 reader 6600 system show the total uncertainty value which is less than that of admis- sible value of 42% for personal dosimetry services.