Evaluation of a field olfactometer in odour concentration measurement

Abstract

Field olfactometry using portable olfactometers is one of the common methods in assessing odour nuisance of odour sources and validating odour dispersion modelling results. To obtain reliable field odour data, a field olfactometer needs to be accurate and reliable. The IDES Scentroid SM 100 is a recently developed portable field olfactometer but its accuracy in measuring odour concentration has not been sufficiently investigated. In this study, the results obtained by SM 100 are compared with the results obtained by a standard laboratory olfactometer in measuring odour concentrations of samples containing n-butanol gas and poultry barn exhaust air. The standard olfactometer used was designed according to European EN 13725 Standard (2003) and was a triangular forced-choice olfactometer that could use 8 panellists simultaneously for olfactometry analysis. Results showed that there was a good agreement between odour concentrations obtained by these two types of olfactometers for full-strength and diluted samples with odour concentrations ranging from 50 to 850 ou m−3 (P > 0.05). SM 100 gave 28%–41% higher values than the laboratory olfactometer for poultry barn odour, while this was not observed for n-butanol. For n-butanol samples, SM 100 gave 53% and 9% higher values for the original and 16 times diluted samples, respectively; in contrast, SM 100 gave 9% lower values for 64 and 128 times dilutes samples. Different discrepancy trends in two tested odour types suggest that more odour types should be tested to provide a better picture of the level of accuracy of SM 100.