Toward a Scheme for Evaluating the Performance of Continuous Particulate Air Monitor Quantitative Methods.

Abstract: There has long been a need for an objective assessment of the performance of quantitative methods used for continuous particulate air monitors. These methods attempt to estimate the input to the monitor, the airborne radioactivity concentration (or its time integral), from its output, the detector response. This evaluation should include consideration of both the "tracking ability" of each method (i.e., its ability to follow a physically realistic time-varying concentration), as well as its ability to reduce the inherent random variability of its estimates. These two factors are in conflict, in the sense that optimizing one will worsen the other. A prototype scheme for this performance evaluation is presented, which uses a simulation of a fixed-filter monitor response to a known concentration profile and then finds an evaluation score using the residuals between that profile and the method's estimates as generated from the monitor response.