Fig. 2.

The Adaptive Olfactory Measure of Threshold (ArOMa-T). The test includes a bi-fold card graphics and text on the outside pages (A) and with user instruction and 17 peel and burst panels that contain varying amounts of the rose-like/floral odorant phenyl ethyl alcohol (PEA) on the inside pages (B). The unfolded card is approximately 9.5 × 11.15 inches (~241 mm by ~286 mm), and the folded card fits easily within a standard 7 in × 10 in envelope for potential delivery via mail. Participants are guided through the task with an accompanying smartphone/tablet app or cloud-based web app that indicates which panel should be peeled and sniffed next. Labels 1–16 contain different PEA concentrations covering a range of ~3.5 log₁₀ units, while label 0 has no added odor as is presented as a reference for the background smell of the label and card. Some labels contain identical concentrations, and some labels are blanks with no PEA added. The blanks and PEA concentrations are distributed across positions in a quasirandom manner so that users cannot infer any information about concentration from position on the card.