NDIR CO2 Sensor for HVAC System

HVAC System, BMS system

Nowadays, NDIR carbon dioxide (CO2) sensor based on non-dispersive infrared technology is widely used in various fields like ventilation system, indoor air quality (IAQ) monitor, industry, agriculture, etc to measure CO2 concentration and save energy consumption. It has advantages of high accuracy, high stability, long lifespan and good gas selectivity (which is not easy to poisoning), wide range, etc, which is the best choice to ensure the stable performance of the CO2 monitoring.

Generally, there are three types of NDIR CO2 sensors: single beam single wavelength sensor, dual beam dual wavelength sensor and single beam dual wavelength sensor. Basically, the key components of the sensor are an infrared source, gas chamber and an infrared detector. When light wave corresponded to certain gas with absorption spectrum passes through measured gas, the intensity of light wave will be significantly weakened. The intensity attenuation is related to concentration of measured gas.

Single beam NDIR CO2 sensor

It is single beam single wavelength sensor integrated with one sensitive component and one narrowband filter lenses. There are many causes of drift problem, such as long time transportation or laid-up, temperature and humidity change, transformation of casing.

Thanks to the automatic background calibration function, the sensor could calibrate itself. The sensor will take the lowest CO2 reading as the zero point (400 ppm) within several days( In ventilated environment, the lowest CO2 concentration is close to 400 ppm). One of the most important condition for automatic background calibration is fresh air.

In this case, single beam CO2 sensor is suggested to be used in indoor air quality monitoring, ventilation system , where there is fresh air.

Dual beam NDIR CO2 sensor

It is mainly reference to single beam dual wavelength sensor. It is with one beam for detecting, another beam for reference.

The advantages are good stability, anti-interference, higher accuracy, etc. It is widely used in not ventilated environment such as ventilation system, automotive , greenhouse facilities, seed storage, controlled atmosphere(CA) cold storage, seed storage, ripening room of fruit and vegetable, CO2 incubator, etc.

Wuhan Cubic can provide these two sensor types based on core NDIR gas technology for CO2 level monitoring different in applications.