18F half-life measurement using a high-purity germanium detector

► The 18F half-life was measured with a reference source and without it using HPGe detectors. ► We found the systematic effect 'activity dynamic range effect' by monitoring the counts of the reference source. ► This activity dynamic range effect was corrected by using the reference source method. ► The 18F half-life using the reference source method was in a good agreement with the recommended value of LNHB.