Abstract: Reference samples were developed for environmental radioactive measurement. The collected soils were undergo drying, crushing, sieving and seven days uninterrupted mixing, sampling in bottle and between bottles. Gamma spectrometer was used to measure ²²⁶Ra and ²³²Th. Both t-test and F-test were used for homogeneity testing and the results showed that samples collected were homogeneity when sampled amount was less than 100 g. The samples were distributed to 29 units for comparison, with Z score evaluation applied to the results. Grubbs rule was used to eliminate the abnormal data before setting the value. Results show that the developed reference samples can be widely used in environmental radioactivity measurements.

Key words: Reference samples, Homogeneity, Comparison