Basics, Methods and Indications for Objective Olfactometry. Olfactory disorders are receiving more widespread attention due to their large impact on quality of life. Olfaction may be evaluated with psychophysical methods that use such tools as Sniffn' Sticks((R)) or the UPSIT(R) and with objective olfactometry. Olfactometry is the recording of evoked potentials after intranasal stimulation using an olfactometer. This device continuously blows warmed and humidified air into the nose and every 30 to 40 s, presents 200-ms triggers embedded in the air. Using substances that are known to elicit the olfactory system alone, such as vanillin, phenylethylalcolhol or H2S, the olfactory nerve is stimulated. Thus olfactory evoked potentials may be recorded via electrodes and the integrity of the olfactory system documented. Using CO2 as a trigger, the trigeminal nerve is stimulated and so-called chemosomatosensory evoked potentials can be recorded. Anosmics typically do hot have any potentials after stimulation with olfactory substances but do have potentials after stimulation with trigeminal stimulating substances. Therefore, olfactometry is becoming of special interest in medicolegal cases.