Background: According to the requirements of GB/T 16145-1995

the sample must be of the same mass density with standard source in the measurement of radiation activity with HPGe γ-ray spectrometer

but the density of the sample is hardly consistent with the standard source in laboratory. Purpose: The aim is to study the effect of the samples in different densities on measurement results. Methods: Firstly

the net count rates (n) of the six samples in various mass densities are measured using HPGe γ-ray spectrometer

and the respective self-absorption coefficients are calculated. Secondly

the sample-model is established using sourceless efficiency calibration software-Gammaclib. And then the detection efficiency and self-absorption coefficient are obtained. Results: The detection results show that with the raise of density

the self absorption coefficients are decreased. Conclusion: The results by both methods indicate that the differences of the density between sample and standard source have obvious influences on the measurement results and need self-absorption correction.Cited