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Selecting the panel

The subjects are selected from a group of at least 50 applicants of ages ranging

from 18 to approximately 35 years old. There is no restriction on distribution of

gender. Participants should abstain from smoking and drinking coﬀee for at

least one hour before any test. Also, they are asked not to use perfume,

strong smelling deodorants or make-up, and not to eat garlic or other spicy

food the day before the tests and on the day of the tests.

The selection is based on the quantitative assessment of the concentration of

a reference gas by smelling. The reference gas is 2-propanone, which is easy to

measure and to produce in various concentrations in the air. Passive evapora-

tion creates known concentration of this gas in air, and this air is presented

to the human nose at a constant airﬂow coming out of a so-called PAP meter,

which consists of a 3 l jar made of glass covered with a plastic cap, a fan and

a diﬀuser (see Figure 6.8). The cap has two holes; in one of them the fan is

placed to suck the air through the jar and to blow it into a glass cone that

diﬀuses the exhausted air. The angle of the cone is at 88, to avoid mixing

with room air. The diameter of the top of the cone is 8 cm, convenient to situate

the nose in the middle. The small fan should produce at least 0.9 l/s, several

times more than the airﬂow during inhalation. The person therefore inhales

exclusively air from the jar, undiluted by room air.

Ø140 mm

3 litre jar

240 mm

430 mm

Cone (top Ø80 mm)

Ø24 mm

Cap (plastic)

Fan

Figure 6.8 The PAP meter

Source: Bluyssen, 1990.

114 Ventilation and Airﬂow in Buildings

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Sharp JX-9400 Technical Information Seite 135