Not dreaming, just living in the real world.
That instrument you linked to is a "broadband" detector and is not specific in any.
It will not give you any indication of the actualcompound that it is detecting, just that is detecting something.
That "something" may include cologne
I mentioned options like that much earlier in thethread using PID.
This device will NOT detect any fumes. None, zero,nada.
Instruments like these require frequentcalibration or verification of accuracy (AKA bump test).
The test is easy to do, but require a source of referencegas which is usually supplied in compressed form.
The instrument after calibration should beaccurate in detecting the reference gas, but correction factors must be appliedor other gases and to apply a correction factor you must know the exactcompound being detected and if not known reading can be erroneously high or low.
In the real world it would help to know a little about atmospheric monitoring and sensing technologies and the limitations.