土壤样品中总β测量刻度研究

Research on the calibration of β ray measurement for soil samples

通过对土壤样品成份的分析及标准参考物质的研究,选择两种刻度源一KCl源和编号为GBW04127的铀钍天然系矿石标准物质分别对仪器进行刻度,用12个国家标准物质模拟土壤样品,测量结果对比可知:在土壤样品总口测量中,用GBW04127源作为刻度源比用KCl测量结果更为准确,用KCl作刻度源数据明显偏低;除^(40)K粉末放射源标准物质和钍含量较低的钍粉末放射源标准物质用KCl刻度测量误差比用GBW04127源误差小以外,对于纯铀粉末放射源标准物质、铀镭平衡粉末放射源标准物质和含量较高的钍粉末放射源标准物质,GBW04127源刻度的测量误差均小于用KCl作为刻度源的测量误差。

Through analysis on composition of the soil sample and standard reference materials,we choose two calibration sources to calibrate the instrument respectively—KCl source and standard materials GBW04127（natural uranium and thorium ore）.We use 12 standard materials to simulate the soil samples.By comparison of the data,we know that for total β measurement of the soil samples,the measured result calibrated by GBW04127 source is more accurate than that of by KCl.The data value that calibrated by KCl source is lower obviously.For standard materials of 40K and thorium powder source（Thorium content is lower）,the result measured by the KCl calibrated instrument is more accurate than that by GBW04127.As for standard materials of pure powder of uranium source,uranium-radium equilibrium powder source and thorium powder source（Thorium content is higher）,GBW04127 calibrated instrument,at more accurate the result than that by KCl source calibrated.