Application of Electronic Nose to Predict the Optimum Fermentation Time for Low-Country Sri Lankan Tea

Table 1

Sensors used in the sensor array.

Sensor	Sensitive substances	Detection range
MQ2	LPG, isobutane, propane, methane, hydrogen, smoke, and alcohol	200 ppm–5000 ppm (LPG and propane), 300 ppm–5000 ppm (butane), 5000 ppm–20000 ppm (methane), 300 ppm–5000 ppm (H2), and 100 ppm–2000 ppm (alcohol)
MQ3	Alcohol and benzene	0.05 mg/L–10 mg/L (alcohol)
MQ4	Methane	300–10000 ppm (CH4)
MQ5	H2, LPG, and alcohol	CH4, CO 200–10000 ppm