FAQ about CO2 Sensor

Q1: What is a CO2 sensor and what is its purpose?

A1: A CO2 sensor is a device used to detect the concentration of carbon dioxide (CO2) in the environment. Its primary function is to assist in monitoring indoor air quality, ensuring that those who work or reside indoors are not exposed to harmful concentrations of CO2.

Q2: What is the measurement principle of the CO2 sensor?

A2: The measurement principle of a CO2 sensor includes three main methods: infrared, chemical adsorption, and electrochemical. Among them, the most commonly used method is the infrared sensor, which detects the absorption of infrared energy by CO2 molecules to measure CO2 concentration. For instance, Gravity: I2C SCD41 Infrared CO2 Sensor (400 - 5000 ppm)andGravity: PWM Infrared Carbon Dioxide Sensor (400-5000 ppm) are examples of infrared CO2 sensors.

Q3: What are the application areas of CO2 sensors?

A3: CO2 sensors are widely used in various scenarios, including indoor air quality monitoring, intelligent building control, greenhouse gas monitoring, and more. In industrial environments, CO2 sensors can also be used to monitor the concentration of CO2 in chemical reactions.

Q4: What should be paid attention to when installing the CO2 sensor?

A4: Proper installation of CO2 sensors is crucial for accurate monitoring of indoor CO2 levels. Here are a few points to consider when installing the sensors:

Placement: CO2 sensors should be installed in areas where CO2 levels need to be monitored, such as enclosed rooms with poor air circulation. However, they should be placed away from areas that are easily disturbed or contaminated, such as near doors, windows, and ventilation ducts.

Avoid direct sunlight: Sensors should not be installed in direct sunlight to avoid temperature changes that may cause errors in measurements.

Avoid contamination: Sensors should be installed in clean, dust-free, oil-free, and chemical-free areas.

Avoid heat sources: Sensors should be placed away from heat sources to prevent high temperatures that may affect measurement accuracy.

Q5: Does CO2 sensor need maintenance?

A5: CO2 sensors require regular calibration to ensure accurate measurement of CO2 concentration. In addition, the sensor should be kept clean, and the sensor filter should be replaced regularly to prevent the accumulation of dust or other particles that may affect measurement accuracy.

Q6: How to calibrate the CO2 sensor?

A6: CO2 sensors need to be calibrated regularly to ensure accuracy. The usual calibration methods include manual calibration and automatic calibration. Take the Gravity: PWM Infrared Carbon Dioxide Sensor (SEN0219) as an example.

Manual calibration Manual calibration zero point is to calibrate the zero point of the sensor by shorting the HD and GND of the sensor, and the low level needs to be maintained for more than 7 seconds. Before calibrating the zero point, please ensure that the sensor has been running stably for more than 20 minutes at a concentration of 400ppm.

Automatic calibration The automatic calibration function means that the sensor can intelligently judge the zero point and calibrate it according to the environmental concentration after running continuously for a period of time. The calibration period is every 24 hours from the start of power-on, and the zero point of automatic calibration is 400ppm. The automatic calibration function is suitable for office and home environments.

Q7: How to troubleshoot?

A7: Issues such as inaccurate measurements, sensor malfunction, and connectivity problems can usually be resolved through simple maintenance steps such as calibrating the sensor, replacing the sensor filter, and checking the connections.

Q8: Why is my sensor (SEN0219) not outputting properly? What is the output frequency?

A8: For issues with the SEN0219 sensor, it is recommended to refer to the FAQ section of the product, which can be found in this forum post.

Q9: How to choose from the many CO2 sensors on the platform?

A9: Choosing a suitable CO2 sensor requires consideration of multiple factors, including the sensor's accuracy, measurement range, response time, reliability, price, and more. Additionally, it is important to select the appropriate sensor type based on the specific needs of the application, such as wall-mounted, portable, or embedded. You can also refer to this CO2 sensor selection guide for further assistance.

If you have other questions, just feel free to post them in our forum for consultation. We will reply them as soon as possible and improve the product FAQ gradually.