ISO 11222:2002提供了一种用于量化在定义的平均时间段内在指定位置获得的一组空气质量数据的时间平均值的不确定性的方法。该方法适用于通过指定的测量系统连续或间歇监测获得的空气质量数据。时间平均值的不确定度既取决于测量结果的不确定度，也取决于由于数据集时间覆盖不完全而产生的不确定度。 ISO 11222:2002仅适用于以下情况 用于计算时间平均值的一组空气质量数据代表了被测对象在定义的时间段内的时间结构，关于测量结果不确定性的适当信息是可用的，并且测量结果都是在相同的位置获得的。 ISO 11222:2002实施了测量不确定度表示指南(GUM)的建议。

ISO 11222:2002 provides a method for the quantification of the uncertainty of a time average of a set of air quality data obtained at a specified location over a defined averaging time period. The method is applicable to air quality data obtained by continuous or intermittent monitoring by means of a specified measuring system. The uncertainty of the time average depends on both the uncertainty of the measurement results and the uncertainty due to incomplete time coverage of the data set. ISO 11222:2002 is only applicable if

• the set of air quality data used to calculate the time average is representative of the temporal structure of the measurand over the defined time period,
• appropriate information on the uncertainty of the measurement results is available, and
• the measurement results have all been obtained at the same location.

ISO 11222:2002 implements recommendations of the Guide to the Expression of Uncertainty in Measurement (GUM).