MQ-135 Air Quality Gas Sensor Module

Highly sensitive gas sensor for detecting benzene, alcohol, and smoke.

The output voltage increases proportionally with the concentration of detected gases, ensuring accurate measurement.

Features fast response and quick recovery times for reliable real-time sensing.

• Adjustable sensitivity to tailor detection thresholds.
• Signal output indicator for easy monitoring.

Pin Configuration:

• Pin No:
• Pin Name:
• Description:

For Module

• Vcc - Powers the sensor, typically at +5V operating voltage.
• Ground - Connects the module to system ground.
• Digital Out - Provides digital output based on a threshold set by the potentiometer.
• Analog Out - Outputs 0-5V analog voltage proportional to gas concentration.

For Sensor

• H-Pins - One connected to supply, the other to ground.
• A-Pins - Interchangeable with B pins, tied to supply voltage.
• B-Pins - Interchangeable with A pins; one outputs signal while the other is grounded.

Features and Specifications

• Detects a wide range of gases like ammonia (NH3), nitrogen oxides (NOx), alcohol, benzene, smoke, carbon dioxide (CO2), and more.
• Highly sensitive with a stable and long-lasting performance.
• Operates on a 5-volt power supply.
• Provides an analog output voltage between 0 to 5 volts, based on gas concentration.
• Also provides a simple ON/OFF digital output (0 or 5 volts) using TTL logic.
• Requires about 20 seconds to warm up before giving accurate readings.
• Can be used as either an analog or digital sensor.
• Digital sensitivity can be adjusted with a built-in potentiometer (small knob).