MQ135 Air Quality Sensor Module

MQ135 Air Quality Sensor Module

The MQ135 Air Quality Sensor Module a low cost semiconductor sensor which can detect the presence of Ammonia (NH3), Mono-nitrogen oxides (NOx), Alcohol, Benzene, Smoke, Carbon-dioxide (CO 2) etc. It has good sensitivity to harmful gases in a wide range. The sensitive material used for this sensor is SnO2, whose conductivity is lower in clean air. It’s conductivity increases as the concentration of sensing gases increases. This module provides both digital and analog outputs. MQ135 Air Quality Sensor module can be easily interfaced with Micro controllers, Arduino Boards, Raspberry Pi etc.

Wiring:
✅VCC: positive power supply (5V)
✅GND: power supply is negative
✅DO: TTL switching signal output
✅AO: analog signal output