[Retracted] Electronic Nose for Differentiation and Quantification of Yeast Species in White Fresh Soft Cheese

Table 1

The characteristics of the eight metal-oxide semiconductor (MOS) sensors, which electronic nose (EN) is composed of.

Sensor name	Target gas sensitivity	Typical detection ranges (ppm)
MQ-2	General combustible gas	200–5000 liquefied petroleum gas (LPG) and propane, 300–5000 butane, 5000–20,000 methane, 300–5000 hydrogen (H2), 100–2000 alcohol
MQ-3	Alcohol vapour	10–300
MQ-4	Natural gas and methane	200–10,000 CH4, natural gas
MQ-5	Liquefied petroleum gas, natural gas, and coal gas	200–10,000 LPG, liquefied natural gas (LNG), natural gas, isobutane, propane, and town gas
MQ-6	LPG, propane	200–10,000 LPG, isobutane, propane, LNG
MQ-8	Hydrogen	100–10,000
MQ-135	Air quality control (NH3, benzene, alcohol, smoke)	10–10,000
MQ-138	Formaldehyde, benzene, aldehyde, ketone, and ester	10–1000 benzene, 1–1000 alcohol, 10–3000 NH3