MQ135 Air Quality Sensor Module

The MQ135 Air Quality Sensor provides a starting point for exploring gas sensing and environmental monitoring. Its response changes when exposed to certain gases and vapours, allowing a connected circuit to observe variations around the sensor.

For students, hobbyists, and electronics developers in Pakistan, this module is useful for classroom demonstrations, data-logging experiments, and IoT prototypes. Combine it with a compatible controller and display to build an interactive monitoring project.

Semiconductor Gas Detection

The MQ135 sensing element responds to multiple substances, including ammonia, sulfides, benzene-series vapours, and smoke. Because several gases can affect its output, a reading does not identify one specific pollutant.

Treat uncalibrated readings as relative sensor responses. The module does not directly provide a calibrated CO₂ concentration, particulate measurement, or standard Air Quality Index.

Arduino and ESP32 Project Integration

Connect the module according to its printed terminal labels and board documentation. Check whether the supplied version provides an analog output, a digital threshold output, or both.

Match output voltages to the controller’s input limits. For an ESP32 or another 3.3V controller, suitable signal conditioning may be required. A WiFi-enabled controller can add network connectivity to your project.

Warm-Up and Calibration

Allow the sensor to warm up and stabilise according to its documentation before collecting readings. Establish a baseline under known conditions, then record changes consistently.

Temperature, humidity, supply stability, and previous exposure can influence results. Estimating gas concentration requires an appropriate calibration method and supporting measurements.

Typical Applications

• Arduino gas-sensing experiments.
• Educational air-monitoring models.
• Relative sensor-response logging.
• IoT dashboard prototypes.
• Sensor comparison projects.
• Electronics laboratory demonstrations.

Use appropriately certified equipment for life-safety gas alarms.

Product Specifications

Buy MQ135 Air Quality Sensor in Pakistan

Choose the MQ135 Air Quality Sensor Module from Mekatroniks for educational sensing and monitoring prototypes. Check the module’s supply, outputs, and pinout before connecting it to your controller.