MQ-135 Gas Sensor Module | NH3, Alcohol, benzene, smoke , CO2 Detector

The MQ-135 gas sensor module detects ammonia, alcohol, benzene, smoke, and CO2 (carbon dioxide) in the surrounding air by measuring their concentration through a heated metal oxide element. It runs at 5V DC and gives an analog output (a variable voltage that rises with gas concentration) readable on any Arduino and ESP32 analog pin. The mq135 gas sensor covers detection from 100 to 1000 ppm (parts per million, a measure of gas density in air).

The honest limitation of the mq135 sensor is that it responds to multiple gases at once and cannot tell you which specific gas triggered the reading. Cross-sensitivity matters in real-world deployments, so use it for general air quality monitoring rather than precise gas identification.

Hobbysist and IoT makers buy this mq135 air quality sensor for lab classroom monitors, home safety alerts, and ventilation control builds. Connect to 5V, GND, and read the analog output pin in Arduino to get started right away. StemVolt provides this sensor with trusted quality, ensuring reliable performance and easy usability.

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Features:

• Detects NH3, alcohol, benzene, smoke, and CO2 covering broad indoor air quality monitoring
• Operates at 5V DC supply allowing direct connection to Arduino and ESP32 boards
• Detecting range of 100 to 1000 ppm suits typical indoor pollution level monitoring
• Analog interface outputs proportional voltage for variable gas concentration measurement

Technical Specifications:

Applications:

• A classroom air quality monitor uses this to alert when CO2 rises above safe levels
• A home safety project uses this to detect smoke or alcohol vapour in a closed room
• A gas sensor module logs indoor air quality to a dashboard over serial monitor on Arduino
• A factory safety system reads benzene or ammonia concentration and triggers an exhaust fan

Package Includes:

• 1 x MQ-135 Gas Sensor Module