Dependence of the LR-115 radon detector calibration factor on track density

•Calibration factor of LR115 track detectors for radon measurement have been studied.•The dependence of the calibration factor vs. radon exposure/track density is derived.•The correction of radon exposure is performed directly on the calibration factor.•The new approach corrects radon exposure for saturation effect on the film surface.•The trend of calibration factor has been justified in terms of saturation effect.

The reliability and accuracy of the methodology based on using LR-115 track detectors for radon measurements have been studied by determining the dependence of their calibration factors on radon exposure at levels reaching 13 MBq m−3 h. This factor results not constant and demonstrated a decreasing exponential trend vs. exposure that has been explained in terms of the saturation effect and verified using a numerical simulation. This dependence does not affect the parameter that normalizes track density vs. film thickness. This parameter results constant and equal to - 0.30±0.02 cm−2/µm in the 300–8000 kBq h m−3 exposure range.