Air Quality Sensor MQ135
MQ135 is a low cost semiconductor sensor which can detect the presence of Ammonia (NH3), Mono-nitrogen oxides (NOx), Alcohol, Benzene, Smoke, Carbon-dioxide (CO2) etc. This module is commonly used as an Air Quality Sensor as it has good sensitivity to harmful gases in 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. MQ135 Air Quality Sensor can be easily interfaced with Microcontrollers, Arduino Boards, Raspberry Pi etc using an Analog to Digital Converter (ADC).