MQ-135 Air Quality Gas Sensor

Broad Toxic & Hazardous Gas Detection: Sensitive to a wide range of harmful airborne gases including ammonia (NH ₃), benzene, alcohol, smoke, nitrogen oxides (NOⅹ), and carbon dioxide (CO₂).

Onboard Signal Comparator: Equipped with an LM393 differential voltage comparator IC to ensure stable digital logic threshold switching free from electrical noise.

Dual Signal Output Pins: Features an Analog Output (AO) pin for continuous concentration monitoring and a Digital Output (DO) pin for direct logic switching.

Adjustable Alarm Setpoint: Includes an onboard precision potentiometer for fine-tuning custom gas threshold triggers for ventilation fans and alarms.

Integrated LED Status Telemetry: Outfitted with an onboard power status LED and a digital switching status LED for instant visual indication during operation and testing.

Board Material: Flame-retardant FR-4 glass-epoxy breakout PCB with dual-layer tin-plated contacts and protective tin-dioxide (SnO₂) sensing layer.

Technical Specifications:

Sensor Element: MQ-135 Semiconductor Gas Transducer.

Operating Supply Voltage: 5.0V DC.

Signal Outputs: Dual Analog (AO) + Digital Switching (DO).

Comparator IC: LM393 Differential Comparator.

Board Color: Blue PCB with Silver Metallic Sensor Cap.

Usage Advice: Connect VCC (5V) and GND, allow a 20-second warm-up period for the internal heating element to stabilize, and read AO for analog gas concentration or DO for digital threshold triggers.

Maintenance: Keep the metal mesh sensor cap clear of grease, dirt, and water vapor condensation; do not expose directly to high-concentration corrosive gases for extended periods.

Essential Indoor Air Diagnostics Module: Position as a versatile gas detector for smart home air quality monitors, hazardous gas leak alarms, office ventilation controllers, and agricultural air stations.

Highlight Multi-Gas Telemetry: Emphasize how a single sensor detects both toxic pollutants like ammonia and benzene alongside general air quality parameters like CO₂ and smoke.

Recommended Cross-Sell Add-ons: Pair with CCS811 Air Quality Sensor, ENS160+AHT21 Carbon Dioxide, Air Quality, Temperature And Humidity Sensor CO2 eCO2 TVOC, PMS5003 Dust laser Sensor Module, and ESD antistatic mat 50x40CM PCB Welding Mat.

Featured Collection Star: Display prominently on your Air Quality Sensor collection page as your standard multi-gas detection breakout module.