This text describes a carbon dioxide sensor module that employs infrared (IR) radiation to detect CO2 levels in the air. It’s ideal for projects needing a broad range of CO2 detection, such as monitoring indoor air quality, landfills, process control, and horticulture in controlled environments.
The module features an MG-811 sensor, a metal oxide sensor that requires heating to a specific temperature. This heating causes CO2 molecules to disengage from the air and be absorbed by the sensor. The MG-811 is more responsive to CO2 than to alcohol or CO, and its output voltage rises with increasing CO2 levels.
Suitable for use in greenhouses and medical applications, the sensor module emits an analog signal that inversely correlates with CO2 concentration. It also provides a digital output pin with TTL output. The integrated potentiometer allows for the adjustment of the digital output threshold. Upon reaching this threshold, the sensor’s LED will activate, and the digital pin will emit a HIGH voltage signal.
Pinout:
VCC: 6V (You can use a 4 AA battery holder for this ).
AOUT: Analog Output (voltage decreases as CO2 Levels increase).
DOUT: Digital Output that goes HIGH when the threshold is reached (set the threshold by turning the onboard potentiometer).
GND: 0V.
Connection Diagram with Arduino and LCD Display:
Features
Wide detecting scope.
High sensitivity & stability.
Simple drive circuit.
Digital output: Active low (When it outputs a low-level signal, the indicator LED will be on)
Analog output: Two Range Options: 0 to 2V or 0V to 4V. The default is 0V to 2V DC.
Compatible with Arduino & Raspberry Pi (for use on analog output with Raspberry Pi you will need an Analog to Digital Converter Chip).
The MG811 Air Carbon Dioxide (CO2) Sensor Module is a versatile gas and dust sensor used across a wide range of applications including air quality monitoring, gas leak detection, industrial safety, HVAC systems, and environmental monitoring.
Common use cases:
Building a gas leak alarm for LPG/methane
Monitoring indoor air quality (CO2, VOC)
Dust monitoring in a workshop
This product is ideal for environmental engineers, safety professionals, and IoT developers.
Technical Tip: MQ-series sensors need a warm-up period (24-48 hours for first use). Calibrate in clean air for accurate readings.
Shipping & Delivery
Free shipping on orders above ₹999 across India
Dispatched within 1-3 business days
Expected delivery: 3-7 business days depending on location
Secure packaging to ensure safe transit of electronic components
Weight
0.02 kg
Dimensions
4 × 3 × 4 cm
15 Days Warranty
Please note that this item is only covered by a standard supplier warranty against manufacturing defects for a period of 15days from the time of delivery. It is important to understand that only manufacturing defects are covered under this warranty, and any other issues will not be considered for reimbursement or replacement. We strongly advise inspecting the product upon delivery to ensure it meets your expectations. In case of any manufacturing defects, we guarantee reimbursement or replacement.
What voids warranty:
If the product is subject to misuse, tampering, static discharge, accident, water or fire damage, use of chemicals & soldered or altered in any way.
Neeraj Joshi (verified owner) –
Average MG811 Air Carbon Dioxide Sensor. Readings fluctuate a bit. Works for rough measurements.
Yash Gill (verified owner) –
Bought this MG811 Air Carbon Dioxide Sensor for my college project. Accurate readings, easy to code. Very happy!
Dhruv Menon (verified owner) –
Perfect MG811 Air Carbon Dioxide Sensor for my automation project. Integrates seamlessly with my microcontroller.
Darshan Hegde (verified owner) –
Perfect for my weather station. This MG811 Air Carbon Dioxide Sensor gives consistent readings day and night.
Aditi Yadav (verified owner) –
Perfect for my weather station. This MG811 Air Carbon Dioxide Sensor gives consistent readings day and night.
Vaishali Kapoor (verified owner) –
Decent MG811 Air Carbon Dioxide Sensor for the price. Requires proper wiring but works well once set up.
Ashish Mittal (verified owner) –
Outstanding accuracy from this MG811 Air Carbon Dioxide Sensor. Compared with a professional instrument, readings match closely.
Manish Rathore (verified owner) –
Superb MG811 Air Carbon Dioxide Sensor! Using it in my environmental monitoring system. Very reliable data.
Darshan Dhillon (verified owner) –
Perfect for my weather station. This MG811 Air Carbon Dioxide Sensor gives consistent readings day and night.
Akshat Hegde –
Very satisfied with this MG811 Air Carbon Dioxide Sensor. Library support is good and it’s easy to interface.
Vivek Luthra –
Excellent sensitivity and range on this MG811 Air Carbon Dioxide Sensor. Works better than I expected.
Om Saxena (verified owner) –
Pretty good MG811 Air Carbon Dioxide Sensor. Documentation could be better but the sensor itself is solid.
Kritika Verma (verified owner) –
Great MG811 Air Carbon Dioxide Sensor. Using it in my smart agriculture system. Reliable measurements every time.
Daksh Khanna –
Excellent MG811 Air Carbon Dioxide Sensor! Readings are accurate and consistent. Perfect for my project.
Sunil Bhandari (verified owner) –
Great MG811 Air Carbon Dioxide Sensor. Using it in my smart agriculture system. Reliable measurements every time.
Naman Kohli (verified owner) –
Excellent sensitivity and range on this MG811 Air Carbon Dioxide Sensor. Works better than I expected.
Zara Kohli (verified owner) –
Nice MG811 Air Carbon Dioxide Sensor. Readings are mostly accurate. Good enough for my hobby project.
Tushar Modi (verified owner) –
Pretty good MG811 Air Carbon Dioxide Sensor. Documentation could be better but the sensor itself is solid.
Vidya Rawat –
Average MG811 Air Carbon Dioxide Sensor. Readings fluctuate a bit. Works for rough measurements.
Gaurav Khurana (verified owner) –
This MG811 Air Carbon Dioxide Sensor is excellent for the price. My data logging project is working perfectly now.
Vansh Negi (verified owner) –
Excellent sensitivity and range on this MG811 Air Carbon Dioxide Sensor. Works better than I expected.
Eshan Bajaj (verified owner) –
Perfect MG811 Air Carbon Dioxide Sensor for my automation project. Integrates seamlessly with my microcontroller.
Pallavi Patel (verified owner) –
Good MG811 Air Carbon Dioxide Sensor. Works as described. Calibration needed some patience but results are good.
Sarthak Banerjee (verified owner) –
Bought this MG811 Air Carbon Dioxide Sensor for my college project. Accurate readings, easy to code. Very happy!
Shubham Gupta (verified owner) –
Superb MG811 Air Carbon Dioxide Sensor! Using it in my environmental monitoring system. Very reliable data.
Ishaan Hegde (verified owner) –
Excellent MG811 Air Carbon Dioxide Sensor! Readings are accurate and consistent. Perfect for my project.
Akash Naidu (verified owner) –
Great MG811 Air Carbon Dioxide Sensor. Using it in my smart agriculture system. Reliable measurements every time.