背景噪声普遍存在于分析仪器中，无论样品是否应用于仪器。本文件涉及在测量不确定度的最主要来源是背景噪声的情况下，估算最小可检测值的数学方法。最小可检测值可以直接从背景噪声的随机特性数学推导出来。 本文件规定了解决问题的基本方法 -提取背景噪声的随机特性， -使用随机特性估计响应变量的标准偏差（SD）或变异系数（CV），以及 -根据以上获得的SD或CV计算最小可检测值。 本文件中描述的方法适用于检查各种测量设备对某种物质的检测，其中仪器输出的背景噪声比其他测量不确定度来源更为重要。可行的选择有可见光和紫外吸收光谱法、原子吸收光谱法、原子荧光光谱法、发光光谱法、液相色谱法和气相色谱法。

Background noise exists ubiquitously in analytical instruments, whether or not a sample is applied to the instrument. This document is concerned with mathematical methodologies for estimating the minimum detectable value in case that the most predominant source of measurement uncertainty is background noise. The minimum detectable value can directly and mathematically be derived from the stochastic characteristics of the background noise. This document specifies basic methods to — extract the stochastic properties of the background noise, — use the stochastic properties to estimate the standard deviation (SD) or coefficient of variation (CV) of the response variable, and — calculate the minimum detectable value based on the SD or CV obtained above. The methods described in this document are useful for checking the detection of a certain substance by various types of measurement equipment in which the background noise of the instrumental output predominates over the other sources of measurement uncertainty. Feasible choices are visible and ultraviolet absorption spectrometry, atomic absorption spectrometry, atomic fluorescence spectrometry, luminescence spectrometry, liquid chromatography and gas chromatography.