ISO 11843-3:2003给出了一种从参考状态重复测量的平均值和标准偏差估算响应变量临界值的方法，在某些情况下，净状态变量的值为零，用于所有合理和可预见的目的。因此，可以确定实际状态（或测试样本）中响应变量的值是否高于可归因于参考状态的值范围。 ISO 11843-2中给出了确定响应变量和净状态变量临界值以及最小可检测值的一般程序。这些程序适用于存在相关直线校准且测量响应的剩余标准偏差为常数或净状态变量的线性函数的情况。ISO 11843本部分给出的用于确定响应变量临界值的程序仅适用于未使用校准数据的情况。 假设数据分布为正态或接近正态。 ISO 11843本部分中给出的程序建议用于难以获得大量实际状态的情况，尽管可以制备大量基本状态。

ISO 11843-3:2003 gives a method of estimating the critical value of the response variable from the mean and standard deviation of repeated measurements of the reference state in certain situations in which the value of the net state variable is zero, for all reasonable and foreseeable purposes. Hence, it can be decided whether values of the response variable in an actual state (or test sample) are above the range of values attributable to the reference state. General procedures for determination of critical values of the response variable and the net state variable and of the minimum detectable value have been given in ISO 11843-2. Those procedures are applicable in situations in which there is relevant straight-line calibration and the residual standard deviation of the measured responses is either constant or is a linear function of the net state variable. The procedure given in this part of ISO 11843 for the determination of the critical value of the response variable only is recommended for situations in which no calibration data are used. The distribution of data is assumed to be normal or near-normal. The procedure given in this part of ISO 11843 is recommended for situations in which it is difficult to obtain a large amount of the actual states although a large amount of the basic state can be prepared.