This paper concerns transient sorption measurements in two intervals (54 to 75% and 75 to 84% relative humidity) made on samples of pine, spruce, ash, aspen, cherry, and willow, with the flow in different directions. In the lower interval, the sorption behavior is quite Fickian; but in the higher interval, it is largely governed by other processes—e.g., the slow sorption in the cell walls. Different simple methods of evaluating such non-Fickian sorption curves are proposed and tested
