Table 3.

Sensor sensitivity of individual sensors within the sensor array of the PEN3 e-nose.

Sensor number	Sensor name	Sensor sensitivity and general description	Sensitivity levels
1	W1C	Aromatic compounds	Toluene, 10 mg kg−1
2	W5S	Very sensitive, broad range of sensitivity, reacts to nitrogen oxides, very sensitive with negative signals	NO2, 1 mg kg−1
3	W3C	Ammonia, used as sensor for aromatic compounds	Benzene, 10 mg kg−1
4	W6S	Mainly hydrogen	H2, 0,1 mg kg−1
5	W5C	Alkanes, aromatic compounds, less polar compounds	Propane, 1 mg kg−1
6	W1S	Sensitive to methane. Broad range.	CH3, 100 mg kg−1
7	W1W	Reacts to sulphur compounds, H2S. Otherwise sensitive to many terpenes and sulphur-containing organic compounds.	H2S, 1 mg kg−1
8	W2S	Detects alcohol partially aromatic compounds, broad range	CO, 100 mg kg−1
9	W2W	Aromatic compounds, sulphur organic compounds	H2S, 1 mg kg−1
10	W3S	Reacts to high concentrations (>100 mg/kg) of methane-aliphatic compounds	Not determined