MG811 CO2 Sensor Carbon Dioxide Gas Sensor

The MG811 CO2 sensor is an electrochemical gas sensor designed to detect carbon dioxide (CO) concentration in the air, with a typical qualitative detection range of 350 to 10,000 ppm.Unlike optical NDIR sensors, the MG811 functions as a solid electrolyte cell. It outputs a voltage that decreases as the CO concentration increases.Technical Specifications

• Operating Voltage: Requires a strict 6.0V DC power supply for its internal preheater.
• Current Consumption: High current consumption (~140150mA) due to the continuous heating element.
• Outputs: Dual signal capabilities featuring an Analog output and a TTL Digital level output.
• Cross-Sensitivity: High selectivity to CO, with low cross-sensitivity to alcohol and carbon monoxide (CO).
• Preheat Time: Requires a burn-in/preheat time to stabilize the chemical heating tank for accurate readings.

Module Pinout GuideStandard breakout modules for the MG811 feature a 4-pin or 3-pin configuration:

• VCC: Power input (6V optimal for heater performance).
• GND: Ground connection.
• AOUT (Analog): Output voltage corresponding to CO parts-per-million levels.
• DOUT (Digital): TTL output that triggers when gas limits exceed a user-defined threshold.

Typical Applications

• Indoor air quality monitoring systems.
• Greenhouse and agricultural environmental tracking.
• Fermentation process controls.