Gas

VOC gas sensors are used to detect formaldehyde, toluene, benzene, etc., is a type of semiconductor sensors, it is widely used in ventilation, ventilation fans, air filters, hood, hood and other equipment. With high sensitivity and stability, able to detect more than 0.1ppm gas, air suitable for detecting a variety of volatile organic components formaldehyde, benzene, xylene

Datasheet

MQ-135 module is widely used in air quality control equipments for buildings/offices, are suitable for detecting of NH3,NOx, alcohol, Benzene, smoke,CO2 ,etc

MQ-4 Methane Natural Gas Sensor

The MQ series of gas sensors use a small heater inside with an electrochemical sensor. They are sensitive to a range of gasses and are used indoors at room temperature. The output is an analog signal and can be read with an analog input of the Arduino.

This is a simple-to-use  hydrogen gas  sensor, suitable for sensing hydrogen concentrations in the air. The MQ-8 can detect hydrogen gas concentrations anywhere from 100-10000ppm.

This sensor has a high sensitivity and fast response time.

Gas Sensor(MQ9) module is useful for gas leakage detection (in home and industry). It is suitable for detecting  LPG, CO, CH4 . Due to its high sensitivity and fast response time, measurements can be taken as soon as possible. The sensitivity of the sensor can be adjusted by using the potentiometer.