Description
The MQ135 Natural Gas Sensor Module in Pakistan is a module capable of detecting various types of toxic gases such as ammonia, carbon dioxide, benzene, nitric oxide, and also smoke or alcohol. The MQ-135 can measure harmful air quality gas concentrations in the range of 10 to 1000 ppm, for example: ammonia, aromatic compounds, sulfur, sulfide, benzene vapors, etc.
 Specifications:
- Sensor MQ-135 ( datasheet )
- Power supply: 5VDC
- Detection of toxic gases such as ammonia, carbon dioxide, benzene, nitric oxide, smoke and alcohol
- Ammonia detection range: 10ppm at 300ppm
- Benzene detection range: 10ppm at 1000ppm
- Alcohol sensing range: 10ppm at 300ppm
- IC LM393
- Digital and analog outputs
- Dimensions: 40 x 25 x 22mm
Calibration:Â Â
As a resistance between the sensor output and the earth determines the degree of sensitivity of the MQ-135, then the resistance load must be adjusted with the potentiometer present on the module board for its particular application, taking as base the datasheet equations. Thus, as soon as the sensor detects the presence of any gas, it is possible to record a change in this resistance, allowing to measure the voltage level on the AOUT pin, which can vary between 0V to 5V. And based on the response time of the sensor can be taken preventive measures quickly.
Connections:Â
The sensor module can be connected to the Arduino by connecting the positive pin (VCC) on the 5V, the negative pin (GND) on the GND and the pin AOUT on an analog pin, such as A0. reading of the analog signal of this pin and follow that reading through the Serial Monitor of the Arduino IDE