Table 2.

Average response times of the sensor array for the three exposure–purge periods.

Sensor	Benzene 50 ppm (min)	Toluene 50 ppm (min)	Xylene 50 ppm (min)
S1	3.13	1.22	2.43
S2	1.66	1.32	2.38
S3	1.48	1.27	2.48
S4	2.12	1.25	2.13