Abstract
Monitoring of aerosol number concentration is important in detecting environmental contamination and controlling air quality. The atmospheric aerosol number concentration always exhibits time variation due to the natural causes such as weather, wind (direction and velocity) and atmospheric stability, and therefore it is difficult to attribute an unexpected increase in aerosol number concentration to a certain causes other than the natural ones. This paper employed the FUMI theory (Function of Mutual Information) to analyze the natural time variation and estimated the detection limit. If an observed value exceeds the detection limit, the null hypothesis that the observed signal comes from non-natural causes would not be denied. The FUMI theory has been used in the field of analytical chemistry to estimate detection limits of a variety of instrumental analyses, and this paper examines whether the FUMI theory is applicable to aerosol time variation which is not necessarily the same as the background noise of analytical instruments. This paper demonstrates that the FUMI theory can be used in an aerosol monitoring system to detect a signal from non-natural causes with a satisfactory precision.
