Abstract: TDCR (triple to double coincidence ratio) liquid scintillation technology is used widely in professional metrology laboratories for absolute measurement of the radioactivities of pure β-emitters. It is reported that the typical combined uncertainty is less than 1%, but the process of obtaining the radioactivity is somewhat complicated for ordinary radiochemical laboratories where combined uncertainty up to 2% is acceptable. Therefore, it is necessary to make TDCR technology more easily for the absolute measurement of the radioactivity of pure β-emitters using a commercial TDCR liquid scintillation counter. The software TDCR07c was adopted to study the relationships among variables such as TDCR, counting efficiency ε_D, and free parameter λ for 11 common pure β-emitters. Meanwhile, the effect of cocktail property parameters on TDCR and ε_D was also studied. Five samples, including two unquenched standards of ³H or ¹⁴C, and three samples of ⁹⁹Tc, ⁹⁰Sr, or ⁹⁰Y at low quench level, were measured to check the TDCR values for common pure β-emitters. Based on the results from TDCR07c, the literature data, and the experimental results, it is suggested that different strategies should be developed for determining the radioactivities of different nuclides. For nuclides such as ⁸⁹Sr, ³²P, and ⁹⁰Y, it is easy to prepare low quenched samples with TDCR＞0.98 where the TDCR-ε_D curve overlaps the diagonal y=x, and the radioactivities can be directly calculated based on ε_D=TDCR. For nuclides such as ¹⁴C, ¹⁴⁷Pm, ³³P, ⁹⁹Tc, and ⁹⁰Sr, it is easy to prepare low quenched samples with TDCR＞0.94 where the TDCR-ε_D curve overlaps the diagonal y=x, and the radioactivities can be directly calculated based on ε_D=TDCR. For nuclides such as ³H, ²⁴¹Pu, and ⁶³Ni, extrapolation is required for obtaining the radioactivity from the count rate (CR). Three models, i.e. the linear model, the five-order polynomial model, and a special function model from literature, were tested to fit the data of TDCR-ε_D or TDCR-CR, and the linear model is shown to be the best one. In this case, a series of quenched samples were prepared with the TDCR of ³H, ²⁴¹Pu, and ⁶³Ni greater than 0.4, 0.2, and 0.3, respectively. Then the TDCR-CR data were fitted with linear model, and the fitted line to the CR of TDCR=1 was extrapolated, which is the radioactivity of the sample. The above method is applicable for absolute measurement of the radioactivities of pure β-emitters in ordinary radiochemical laboratories, with the relative error less than 2%.