BS ISO 11929-3:2019规定了电离辐射计量领域的一个程序，用于计算非负电离辐射测量的“判定阈值”、“检测限”和“覆盖区间限”，并在进行预选时间或计数的计数测量时进行计数。测量结果来自总计数率和背景计数率，以及基于评估模型的进一步数量。具体而言，被测量物可以是净计数率，即总计数率和背景计数率之差，也可以是样本的净活动。 它还可能受到测量系统校准、样品处理和其他因素的影响。交叉引用:JCGM 100:2008ISO 3534-1JCGM 102:2011ISO/IEC指南99ISO 80000-10ISO/IEC指南98-3-2ISO/IEC指南98-3ISO 80000-1JCGM 101:2008ISO/IEC指南98-3-1ISO 18589（所有部分）ISO 10703ISO 7503（所有部分）ISO 28218ISO 11665（所有部分）ISO 9697ISO 969698购买本文件时提供的所有当前修订版。

BS ISO 11929-3:2019 specifies a procedure, in the field of ionizing radiation metrology, for the calculation of the "decision threshold", the "detection limit" and the "limits of the coverage interval" for a non-negative ionizing radiation measurand when counting measurements with preselection of time or counts are carried out. The measurand results from a gross count rate and a background count rate as well as from further quantities on the basis of a model of the evaluation. In particular, the measurand can be the net count rate as the difference of the gross count rate and the background count rate, or the net activity of a sample. It can also be influenced by calibration of the measuring system, by sample treatment and by other factors.Cross References:JCGM 100:2008ISO 3534-1JCGM 102:2011ISO/IEC Guide 99ISO 80000-10ISO/IEC Guide 98-3-2ISO/IEC Guide 98-3ISO 80000-1JCGM 101:2008ISO/IEC Guide 98-3-1ISO 18589 (all parts)ISO 10703ISO 7503 (all parts)ISO 28218ISO 11665 (all parts)ISO 9697ISO 9696ISO 9698All current amendments available at time of purchase are included with the purchase of this document.