Table 2. List of sensors: model number, calibration and their ranges.

Parameter	Sensor model	Calibration method	Measurement range
Temperature and humidity	SHT20	Factory calibrated	−40 °C to 125 °C
Oxygen ( $O_2$) Level	Grove $O_2$ EN0322	Periodic calibration	0% to 30%
Carbon dioxide ( $C{O}_2$)	MQ-135	Manual calibration	0 to 10,000 ppm
Carbon monoxide (CO)	Winson-ZE07-CO	Periodic calibration	0 to 500 ppm
Ammonia ( $N{H}_3$)	Winson-ME3NH3	Periodic calibration	0 to 100 ppm