目的:应用国家标准对α、β表面污染测量仪进行校准,分析在用测量仪的性能状况,提出进一步加强辐射防护工作的建议。方法:选取18台医院核医学科、疾病预防控制中心、职业病防治研究院、卫生监督所以及具有辐射卫生检测资质的企业机构的...目的:应用国家标准对α、β表面污染测量仪进行校准,分析在用测量仪的性能状况,提出进一步加强辐射防护工作的建议。方法:选取18台医院核医学科、疾病预防控制中心、职业病防治研究院、卫生监督所以及具有辐射卫生检测资质的企业机构的α、β表面污染测量仪,型号不做特殊筛选,依据国家标准GB/T 5202-2008/IEC 60325:2002"辐射防护仪器α、β和α/β(β能量>60 ke V)污染测量仪与监测仪"进行校准,校准中采用两组镅-241(^(241)Am)α平面源和两组铊-204(^(204)Tl)β平面源作为标准源,利用支架固定测量距离,根据标准程序完成仪器效率、统计涨落和相对固有误差3项指标的测量。结果:18台测量仪测量α射线的仪器效率主要集中在20%~40%,测量β射线的仪器效率主要集中在20%~60%;18台测量仪测量α射线的统计涨落均<10%,β射线的统计涨落有14台<10%,4台集中在10%~20%;在测量仪的相对固有误差的测量中,大部分仪器测量结果<6%。结论:18台在用的测量仪性能符合国家标准,但仍有个别仪器的个别指标性能低于同类仪器水平,建议使用中要注意维护保养,确保仪器的正常功能和测量准确性,为辐射防护工作提供有力保障。展开更多
By using four specially designed narrow bandpass filters and photodetectors in the instrument, the incident and reflected radiances of sun light on the vegetation are optically sensed, at the red and near infrared ban...By using four specially designed narrow bandpass filters and photodetectors in the instrument, the incident and reflected radiances of sun light on the vegetation are optically sensed, at the red and near infrared bands, then the normalized difference vegetation index(NDVI) is processed by a microprocessor. Compared with conventional spectrometer measuring method of NDVI, the instrument is easy to be used, compact, light and low-cost.展开更多
University teaching and research equipment maintenance costs, rising with the rapid development of the school. Equipment as a teaching resource, should give full play to its role in the efficiency at the same time, fr...University teaching and research equipment maintenance costs, rising with the rapid development of the school. Equipment as a teaching resource, should give full play to its role in the efficiency at the same time, from quality improve equipment management, reduce material consumption, two aspects of efforts to reduce maintenance costs, reduce maintenance expenses. This article by the necessity of self- maintenance, feasibility analysis and establish a competitive mechanism, and that this is a feasible way out equipment maintenance work of vocational collejzes need to adaot to the situation.展开更多
文摘目的:应用国家标准对α、β表面污染测量仪进行校准,分析在用测量仪的性能状况,提出进一步加强辐射防护工作的建议。方法:选取18台医院核医学科、疾病预防控制中心、职业病防治研究院、卫生监督所以及具有辐射卫生检测资质的企业机构的α、β表面污染测量仪,型号不做特殊筛选,依据国家标准GB/T 5202-2008/IEC 60325:2002"辐射防护仪器α、β和α/β(β能量>60 ke V)污染测量仪与监测仪"进行校准,校准中采用两组镅-241(^(241)Am)α平面源和两组铊-204(^(204)Tl)β平面源作为标准源,利用支架固定测量距离,根据标准程序完成仪器效率、统计涨落和相对固有误差3项指标的测量。结果:18台测量仪测量α射线的仪器效率主要集中在20%~40%,测量β射线的仪器效率主要集中在20%~60%;18台测量仪测量α射线的统计涨落均<10%,β射线的统计涨落有14台<10%,4台集中在10%~20%;在测量仪的相对固有误差的测量中,大部分仪器测量结果<6%。结论:18台在用的测量仪性能符合国家标准,但仍有个别仪器的个别指标性能低于同类仪器水平,建议使用中要注意维护保养,确保仪器的正常功能和测量准确性,为辐射防护工作提供有力保障。
文摘By using four specially designed narrow bandpass filters and photodetectors in the instrument, the incident and reflected radiances of sun light on the vegetation are optically sensed, at the red and near infrared bands, then the normalized difference vegetation index(NDVI) is processed by a microprocessor. Compared with conventional spectrometer measuring method of NDVI, the instrument is easy to be used, compact, light and low-cost.
文摘University teaching and research equipment maintenance costs, rising with the rapid development of the school. Equipment as a teaching resource, should give full play to its role in the efficiency at the same time, from quality improve equipment management, reduce material consumption, two aspects of efforts to reduce maintenance costs, reduce maintenance expenses. This article by the necessity of self- maintenance, feasibility analysis and establish a competitive mechanism, and that this is a feasible way out equipment maintenance work of vocational collejzes need to adaot to the situation.
