This Air quality detector module uses an MQ135 sensor which utilises SnO2 as its gas sensitive material. SnO2 has low electrical conductivity with clean air. So when surrounded by polluted air, the electrical conductivity of MQ135 will increase and thus changing the electrical conductivity which is converted to corresponding output signal.
MQ135 has a high sensitivity to Ammonia, sulfide, benzene vapor, smoke and other harmful gas. It can detect various harmful gases, making it a cost-effective choice suitable for multiple applications.
Product type: Semiconductor gas sensor
Target gas: Ammonia; methylbenzene; hydrogen
Standard circuit: Loop voltage Vc ≤24V DC
Heater voltage: VH 5.0V±0.2V AC or DC
Load resistance: Adjustable RL
Features of sensitive components under standard test condition: Heating resistor RH 31Ω±3Ω (room temperature)
Heater power consumption: PH ≤900mW
Surface resistance of sensitive material: Rs 2KΩ-20KΩ(in 100ppm NH3)
Sensitivity: S Rs(in air)/Rs(100ppmNH3)≥5
Concentration slope: α ≤0.6(R100ppm/R50ppm NH3)
Standard testing temperature/humidity : 20 Centigrade±2 Centigrade/65%±5%RH
Standard testing circuit: Vc:5.0V±0.1V
Preheating time: ≥48H