Perceived Air Quality: Should We Use a Linear or a Nonlinear Scale for the Relation between Odour Intensity and Concentration?

Assessing the perceived air quality in decipols by trained panels can be performed rather perfectly today. To calculate the olf load from these results is a little more problematic as one requires olf loads which can simply be added (linearly). The reason for this difficulty is the nonlinear relation between the perceived air quality in decipol and the pollution load in olf. The relation can be expressed by an exponential function in a range between l to 15 decipols. Unfortunately the exponent and the constant in the exponential function differ for different substances. For the most substances they can fairly well be approached by a root law. This is shown for three very different examples: the required outdoor air flow for ventilated rooms with different outdoor air qualities, the exponential law for linoleum and the balance of pollution of a rotary heat exchanger