NDIR sensor working principle

NDIR is a sensor for detecting the concentration of gases in the environment. It is a non-dispersive infrared gas sensor with high accuracy and sensitivity.NDIR sensor’s working principle is to determine the gas concentration by measuring the infrared radiation absorbed or emitted by the measured gas.

Industrial Infrared SF6 Sensor FS7NDIRSF6 (2)
Industrial Infrared SF6 Sensor FS7NDIR/SF6
Industrial Infrared HFCs (Refrigerant) Sensor FS4NDIRR454B (2)
Industrial Infrared HFCs (Refrigerant) Sensor FS4NDIR/R454B

NDIR sensor structure

NDIR sensor is mainly composed of light sources, sample chambers, filters, infrared detector,s and signal processing circuits. In the working process, the light source will emit a beam of infrared light through the sample chamber, the gas in the sample chamber will absorb or emit infrared light of a specific wavelength, and then after the action of the filter, only the infrared light of a specific wavelength can reach the infrared detector. Only the specific wavelength of infrared light can reach the infrared detector. The infrared detector receives the infrared light and generates an electrical signal, which is amplified and processed by the signal processing circuit, and finally outputs the electrical signal of the gas concentration.

Industrial Infrared Methane Sensor FS4NDIRCH4 (2)
Industrial Infrared Methane Sensor FS4NDIR/CH4
Industrial Infrared propane (Refrigerant) Sensor (4)
Industrial Infrared propane(Refrigerant) Sensor FS4NDIR/R290

NDIR sensor working principle

The NDIR sensor working principle is based on the Lambert-Beer law, which states that the concentration of a gas is directly proportional to the intensity of the absorbed light. The filter in the sensor selects a specific wavelength of infrared light so that only the light that can be absorbed or emitted by the gas being measured reaches the infrared detector, thus increasing the accuracy of the measurement. The infrared detector converts the received infrared light into an electrical signal, which is amplified and processed by a signal processing circuit to obtain an electrical signal output related to the gas concentration.

Industrial Infrared Carbon Dioxide Sensor FS4NDIRCO2 (4)
Industrial Infrared Carbon Dioxide Sensor FS4NDIR/CO2
FS00302-3
NDIR CO2 Sensor Module FS00302

Advantages

The NDIR sensor has high measurement accuracy and stability. It allows accurate and reliable gas concentration measurements in a wide range of environmental conditions. Compared to other gas sensors, the nadir sensor is less affected by environmental factors such as temperature, humidity, and air pressure, providing more reliable measurements. In addition, because NDIR sensors only measure infrared light at specific wavelengths, interference from other gases can be avoided, improving measurement accuracy.

Applications

NDIR sensors are widely used in environmental monitoring, industrial safety, and indoor air quality monitoring. In environmental monitoring, ndir sensors can be used to measure the concentration of gases such as carbon dioxide, carbon monoxide, etc. to help monitor air quality and pollution levels. In industrial safety, NDIR sensors can be used to detect the concentration of combustible gases and identify potential safety risks in a timely manner. In indoor air quality monitoring, NDIR sensors can be used to measure indoor carbon dioxide concentrations, provide sensible ventilation advice, and improve indoor air quality.

 

The ndir sensor determines the gas concentration by measuring the infrared radiation absorbed or emitted by the gas under test and is characterized by high accuracy and sensitivity. Its working principle is based on the Lambert-Beer law, and through the cooperation of the filter and the infrared detector, it can provide accurate and reliable gas concentration measurements. ndir sensors have a wide range of applications in the fields of environmental monitoring, industrial safety, and indoor air quality monitoring.