Abstract In view of emanometer calibration difficulty present in earthquake stations, we advance a standard instrument calibration method for emanometer, compare it with RN-FD circulating radon gas solid source, and use RN-150 small radon gas solid source, which is the most widely used gas in current stations, to verify the feasibility of this method. The results show that the three scintillation chambers of FD-125 emanometer are calibrated by using RN-150 small radon gas solid source and AlphaGUARD P2000F emanometer; the relative deviations of the calibration coefficient are 0.2%, 3.4% and 2.8%, meeting the technical requirements of radon observation in seismic monitoring, verifing that the standard instrument calibration method is feasible.
