Background: At present most radiation dose meters have the serious problem of energy response

and they just use the count rate plus relative correction method to measure the dose rate. This method has large error

and cannot distinguish the type of radionuclide

also cannot obtain the contribution of each radionuclide to the dose rate. Purpose: The research of new method is to measure the dose rate and improve the accuracy of measurement. Methods: The method of γ dose rate measurement through measuring full energy peak of γ spectrum was put forward

the angular response function of parallel γ ray injected into detector was defined. The average angular response over full space in the energy range from 0.02 MeV to 3 MeV was calculated by Monte Carlo simulation for ?50mm×50mm NaI(Tl) detector. Measurement tests have been done using standard radioactive sources of 137Cs

60Co

152Eu

133Ba and in reference radioactive field of 137Cs

60Co

226Ra

241Am in a national lab. Results: The test errors are smaller than 2% compared with the theoretical value for standard sources

and smaller than 3% compared with the value of PTW 10 L spherical chamber for reference radiation field. Conclusion: The results show that the method is suitable for the dose rate measurement for a wide range of energy without experimental calibration

can calculate the dose rate of different energy ray

and at the same time identify the radioactive nuclides in the radiation source. Abstract