Abstract: By using two sample media, the detection efficiency of natural and artificial β nuclides with different mass thickness was simulated by experiment and Monte Carlo Method. The relationship between detection efficiency, count rate, detection efficiency correction factor, reciprocal of detection efficiency and mass thickness, as well as detection efficiency and energy were analyzed. The results show that ⁴⁰K is used as the standard source, the detection efficiency correction factor are needed to correct the detection efficiency. The measurement of β radioactivity of ²³⁴Th, ²¹⁰Pb, ²¹²Pb, ²²⁸Ra, ⁶⁰Co, ⁹⁹Tc, etc. should be modified by thin source method and detection efficiency correction factor. The reciprocal of detection efficiency is linear with the mass thickness, which can be used to scale the detection efficiency better. The detection efficiency is exponentially related to the average energy of beta rays. The β ray equivalence of KCl and CaSO₄ media is good and can meet the requirements of relevant standards.

Key words: β nuclide, mass thickness, detection efficiency, correction factor