MQ-135 Air Quality Gas Sensor Module

MQ-135 Air Quality Gas Sensor Module The MQ-135 Air Quality Sensor is a popular sensor module used for detecting air quality and measuring various gases, including ammonia (NH₃), nitrogen oxide (NO), alcohol, benzene, carbon dioxide (CO₂), and smoke. It is commonly used in air quality monitoring applications, environmental monitoring, and industrial control systems. The sensor detects the concentration of benzene, alcohol and smoke in the air, the result can be obtained measuring the voltage on the analog output. The system is supplied with the voltage from 2.5V to 5V. It has a digital and analog output, making it compatible with most of the commissioning modules including Raspberry Pi and Arduino. Features • Wide detection range for multiple gases. • High sensitivity with fast response time. • Stable performance with long operational life. • Dual analog and digital output options. • Adjustable sensitivity through onboard potentiometer. • Simple drive circuit for easy interfacing. • Compact design with mounting holes for easy installation. Specifications Parameter: Value Operating Voltage: 5VDC Power Consumption: ≤800mW Detection Range: 10–1000ppm Analog Output: 0–5V Digital Output: 0V or 5V (TTL Logic) Preheat Time: ≥24 hours Operating Temperature: -10°C to 45°C Storage Temperature: -20°C to 70°C Humidity Range: <95%RH Heater Resistance: 33Ω±5% Load Resistance: Adjustable Dimensions: 35mm x 22mm x 23mm PINOUT Pin No: | Pin Name: | Description For Module 1 | Vcc | Used to power the sensor, Generally the operating voltage is +5V. 2 | Ground | Used to connect the module to system ground. 3 | Digital Out | You can also use this sensor to get digital output from this pin, by setting a threshold value using the potentiometer. 4 | Analog Out | This pin outputs 0-5V analog voltage based on the intensity of the gas. For Sensor 1 | H -Pins | Out of the two H pins, one pin is connected to supply and the other to ground 2 | A-Pins | The A pins and B pins are interchangeable. These pins will be tied to the Supply voltage. 3 | B-Pins | A pins and B pins are interchangeable. One pin will act as output while the other will be pulled to ground. Applications • Indoor air quality monitoring systems. • Industrial emission detection. • Smart home environmental sensing. • Automotive cabin air quality assessment. • Portable air pollution detectors. Datasheet • MQ-135 Sensor.