Evaluation of calibration curve uncertainty using the Monte Carlo method: Application

to turbidity measurement Continuous measurement of the turbidity of urban wastewater is benefi cial to building knowledge of pollutant fl ows and to the management of urban wastewa-ter systems. Classical analytical formulas are not appropriate for evaluating the uncertainty of this type of measurement since a certain number of hypotheses are not being satisfi ed. In particular, the level of uncertainty on the standards might exert a signifi cant infl uence. Given that a well-adapted analytical method becomes rather complex to implement within an operational framework, turbid-ity measurement uncertainty has been assessed herein by running calibration simulations using the Monte Carlo method. This simple and quite general method is based on the same experimental data and hypotheses as the more complex analytical method and enables explaining the causes of deviations observed with respect to the classical analytical method. Lastly, total short-term uncertainty for turbidity measurement of samples proves highly satisfactory (less than 1.5