全国标准级测氡仪的统一校准及低浓度测量比对OACSTPCD

To improve the capacity of radon metrology in China,the standard radon monitors from 11 standard laboratories were calibrated uniformly.The low-level concentration comparison was conducted base on the unified calibration.The unified calibration was carried out at 700～3 000 Bq/m3 radon concentration,and the reference value of radon concentration can be traced to the primary standard of radon activity,Urel=1.6％(k=2).The range of response to reference radon atmosphere for standard radon monitors are 0.93～1.02,and the uncertainties range are 2.2％～3.6％(k=2).The low-level concentration comparison was carried out at 100～400 Bq/m3,the most standard radon monitors| En |＜1.By optimizing the strategy,it is feasible for standard radon moniters to transfer above 100 Bq/m3.However,it is necessary to improve the ability of measurement and concentration control for each laboratory to carry out transfer at concentration of 100 Bq/m3 or below.