Development of the relationship between odor intensity and threshold dilution ratio for swine units

The following models of odor intensity for swine units were evaluated: the Weber-Fechner law model, the power law model, the Stevens model, and the Be idler model. Data were collected from four swine rooms (farrowing, finisher , gestation, and nursery) and odor threshold dilution ratios were measured by a panel using a dynamic forced-choice olfactometer. Odor intensity scale s were determined by eight panelists using a six-point category scale metho d. A nonlinear parameter estimation method was used to estimate the paramet ers in each of the models. The widely used Weber-Fechner law did not adequa tely fit the data of odor intensity and threshold. Both the power law and t he Beidler models described the data effectively, but the Beidler model sho wed the best fit of the data and was used as the model to represent the rel ationship between odor intensity arid threshold dilution ratio for swine bu ildings.