ASSESSMENT OF PRECISION OF A PASSIVE SAMPLER BY DUPLICATE MEASUREMENTS

Duplicate measurement is a common method to determine precision of a s ampling method in an air pollution field study. Several evaluating mea sures for the precision of the sampling method are explored with dupli cate measurements of two types of passive samplers, such as nitrogen d ioxide diffusive badge and carbon monoxide passive sampler. Presentati on of duplicates in a graph as one of the evaluating measures can be a ffected by different assignment of each measurement to vertical and ho rizontal axes. Although absolute difference or relative error among du plicates can quantitatively represent the precision, interpretation of these values depends on the measured concentration range. Intraclass correlation coefficient, often used for an indicator of the reliabilit y of measurements, is an appropriate statistical measure to present a relative similarity of duplicate measurements. Intraclass correlation coefficient is an appropriate way to indicate precision of passive sam plers which is usually determined by duplicate field measurements in a ir pollution studies.