What Is a Carbon Dioxide Sensor?
A carbon dioxide sensor measures CO2 concentration, typically using methods like non-dispersive infrared absorption, which utilizes CO2’s property of absorbing specific infrared wavelengths. Other methods include the solid electrolyte method, where CO2 is ionized in contact with an electrolyte, and the capacitance method, measuring capacitance changes as CO2 dissolves in a polymer.
Uses of Carbon Dioxide Sensors
Carbon dioxide sensors are versatile, and used in various settings:
- Factory exhaust gas inspections.
- Fire alarms in residential facilities.
- CO2 control in plastic greenhouse agriculture.
- Automobile exhaust gas measurement.
- Monitoring CO2 levels in vehicles and rooms, like in air-conditioning systems.
- Carbonated beverage manufacturing.
Principle of Carbon Dioxide Sensors
Different CO2 sensors operate based on the chosen method:
- Non-Dispersive Infrared Absorption: This method involves a light source, a gas container, an optical filter, and a light-receiving element. The sensor measures CO2 concentration by detecting the light absorbed by CO2.
- Solid Electrolyte Method: In this method, CO2 interacts with an electrolyte and a carbonate layer, creating an electromotive force proportional to the CO2 concentration.
- Capacitance Method: This technique uses a conductive polymer compound and an electrode. Changes in capacitance, as CO2 dissolves in the polymer, indicate the CO2 concentration.
Additional Information on Carbon Dioxide Sensors
1. CO2 Sensors in COVID-19 Countermeasures
CO2 sensors are employed as ventilation indicators in closed environments to reduce the risk of COVID-19 transmission. They prompt ventilation when CO2 concentrations exceed set levels, helping to manage indoor air quality.
2. Smartphone-Linked CO2 Sensors
With increased emphasis on ventilation for COVID-19 precautions, CO2 sensors that link to smartphone apps have gained popularity. These sensors provide real-time measurements and alerts, viewable via the app or cloud, enhancing convenience in monitoring CO2 levels.