Reference Method Accuracy and Precision (ReMAP): Phase 1 (CRTD Vol. 60)
Reference Method Accuracy and Precision (ReMAP): Phase I
An integral part of efforts to regulate and control air pollution emissions is collection and analysis of exhaust stream samples to determine the concentration and flow rate of pollutants released to the atmosphere. The U.S. Environmental Protection Agency (EPA) and its counterparts in other countries have developed formal methods defining the hardware and procedures for collecting and analyzing samples to quantify emissions of individual pollutants. A significant number of these methods involve manual extraction of a sample from a facility’s exhaust stack, sample recovery and subsequent laboratory analysis to quantify concentration of a specific pollutant(s) in the sample. All manual processes, including the various EPA measurement methods, are subject to random variations, which ultimately impact the end results. Relatively minor variations in the skill of the sampler, as well as the equipment and procedures used to extract the sample can influence the indicated quantity of sample extracted from the stack and the efficiency with which the pollutant of interest is collected or recovered. Similarly, minor variation in laboratory hardware and procedures influence quantification of the mass or volume of pollutant in that sample. The net result of such random variation is imprecision in measurement results. The current report documents a study where available data have been gathered and analyzed to quantify the precision of key EPA manual measurement methods. The study has been conducted under the auspices of the American Society of Mechanical Engineers (ASME) and is entitled Reference Method Accuracy and Precision (ReMAP), Phase 1.