THE UNCERTAINTY IN MEASUREMENTS MADE USING THE INTEGRATING NEPHELOMETER IN FOG

Despite significant analysis of the errors associated with nephelomete r measurements in the literature, a considerable body of data continue s to be collected using the integrating nephelometer, without any atte mpt to quantify the uncertainty in the measurements. The problem is ex acerbated in aerosols in which there is a dominance of large scatterin g particles, such as fog, since the angular truncation error is increa sed. This paper considers the uncertainties reported by other authors, and attempts to quantify the total uncertainty of measurements in fog by combining these individual contributions. The conclusion is drawn that the nephelometer is not suitable for measurements in fog, due to the large uncertainty in the measured parameters.