The intensity of an odor can be perceived directly without knowing its corresponding concentration. A relationship doing the link between odor concentration and odor intensity could helpful in the analysis of early research and also in the definition of standards and regulations as odor threshold could be used with the odor intensity in defining more the odorous situation. Different mathematical models were evaluated (Weber-Fechner law model, the power law model, the Stevens model, and the Beidler model) in associated to odor threshold and odor intensity evaluations (on a 6 points scale) of a panel using olfactometry to analyze odorous samples from farrowing, finisher, gestation and nursery rooms. The results from those models and the panel evaluations showed that the widely used Weber-Fechner law model did not fit the odor intensity and threshold panel’s data for swine building. Better estimations for the odor intensity were obtained with the power law and the Beidler model; this last model showing the best fit of the experimental data; it was thus chosen to represent the relationship between odor threshold and odor intensity.

As mentioned in the paper more experiments would be needed to verify the conclusion of this study. The development of such tool is important because when those kind of tools are reliable less costly direct measurements have to be done to represent a given situation.