ISO 19581规定了一种筛选测试方法，用于使用伽马射线光谱法快速定量固体或液体测试样品中发射伽马射线的放射性核素（如131I、132Te、134Cs和137Cs）的活度浓度，与HPGe探测器相比，闪烁探测器分辨率较低（参见IEC 61563）。 该测试方法可用于测量任何潜在污染的环境基质（包括土壤）、食品和饲料样品以及经过适当处理的工业材料或产品。ISO 19581中没有规定筛选方法中使用的样品制备技术，因为不需要简单机械加工（切割、研磨等）以外的特殊样品制备技术。尽管取样程序对于测量样品中的放射性至关重要，但它超出了ISO 19581的范围；还有其他可与ISO 19581结合使用的取样程序国际标准（参见参考文献[1]、[2]、[3]、[4]、[5]、[6]）。 该测试方法适用于发射γ的放射性核素如131I、134Cs和137Cs的测量。在Marinelli烧杯中使用0.5 L至1.0 L的样本量和5分钟至20分钟的计数时间，决策阈值为10 Bq·kg？1可以使用商业上可获得的闪烁光谱仪[例如，铊活化碘化钠(NaI(Tl))光谱仪2″× 2″检测器尺寸，662keV下7%分辨率(FWHM)，30mm铅屏蔽厚度]来实现。 该测试方法也可以在“临时”实验室中或甚至在测试实验室外对在收集样品的现场直接测量的样品进行。 在核或放射性紧急情况下，该测试方法能够快速测量潜在污染样品的样品活度浓度，以检查操作干预决策者设定的水平（油），将触发预定的应急响应，以降低现有的辐射风险[12]。 由于该测试方法获得的结果存在不确定性，需要更准确测试结果的测试样品可以在测试实验室中使用高纯锗（HPGe）检测器伽马射线光谱法进行测量，然后适当制备测试样品[7][8]。 ISO 19581不包含确定油的活性浓度的标准。

ISO 19581 specifies a screening test method to quantify rapidly the activity concentration of gamma-emitting radionuclides, such as ¹³¹I, ¹³²Te, ¹³⁴Cs and ¹³⁷Cs, in solid or liquid test samples using gamma-ray spectrometry with lower resolution scintillation detectors as compared with the HPGe detectors (see IEC 61563). This test method can be used for the measurement of any potentially contaminated environmental matrices (including soil), food and feed samples as well as industrial materials or products that have been properly conditioned. Sample preparation techniques used in the screening method are not specified in ISO 19581, since special sample preparation techniques other than simple machining (cutting, grinding, etc.) should not be required. Although the sampling procedure is of utmost importance in the case of the measurement of radioactivity in samples, it is out of scope of ISO 19581; other international standards for sampling procedures that can be used in combination with ISO 19581 are available (see References [1],[2],[3],[4],[5],[6]). The test method applies to the measurement of gamma-emitting radionuclides such as ¹³¹I, ¹³⁴Cs and ¹³⁷Cs. Using sample sizes of 0,5 l to 1,0 l in a Marinelli beaker and a counting time of 5 min to 20 min, decision threshold of 10 Bq·kg^？1 can be achievable using a commercially available scintillation spectrometer [e.g. thallium activated sodium iodine (NaI(Tl)) spectrometer 2" ？ × 2" detector size, 7 % resolution (FWHM) at 662 keV, 30 mm lead shield thickness]. This test method also can be performed in a "makeshift" laboratory or even outside a testing laboratory on samples directly measured in the field where they were collected. During a nuclear or radiological emergency, this test method enables a rapid measurement of the sample activity concentration of potentially contaminated samples to check against operational intervention levels (OILs) set up by decision makers that would trigger a predetermined emergency response to reduce existing radiation risks^[12]. Due to the uncertainty associated with the results obtained with this test method, test samples requiring more accurate test results can be measured using high-purity germanium (HPGe) detectors gamma-ray spectrometry in a testing laboratory, following appropriate preparation of the test samples^[7][8]. ISO 19581 does not contain criteria to establish the activity concentration of OILs.