Statistical Performance of Methods for Measuring Sulfur Concentrations in Ultra Low Sulfur Diesel—Report from the 2004 Inter-laboratory Crosscheck Program

Abstract

Data from the first year of operation (2004) of ASTM's Inter-laboratory Crosscheck Program for Ultra Low Sulfur Diesel (ULSD) is analyzed in greater depth than was possible in the monthly reports. We examine the performances of individual laboratories over the entire year, as well as long-term single-lab performance (site precision). Site-precision was found to be the largest contributor to reproducibility for the two most popular methods. While overall performance was better than anticipated from published precisions, some laboratories performed consistently better than others.