Humidified air was bubbled through 95% ethanol to vaporize ethanol with combined flow rate of 80 U vaporized ethanol and 70 U humidified air (where 100 U is equal to 1.7 L/min at room temperature). Humidified air was streamed over odors placed in a 2.5 cm diameter and 13 cm height cylinder at a flow rate of 130 U for training and 100 U for tests. Odors used were 3 mL iso-amyl alcohol (1:36 in mineral oil) and a mixture of 2 mL ethyl acetate (1:36 in mineral oil) and 1 mL acetic acid (1:400 in mineral oil). Odors were replaced daily.
