NDIR GAS SENSOR

NDIR gas sensors measure target gas concentration through infrared light absorption. They direct IR light through a sample gas volume and detect intensity reduction at the gas’s characteristic absorption wavelength. This principle delivers continuous, stable, selective measurement. Moreover, it avoids the poisoning, drift, and cross-sensitivity limitations of catalytic bead and electrochemical sensing technologies.

Each target gas absorbs IR radiation at a specific molecular absorption wavelength. CO2 absorbs at 4.26 µm. CO absorbs at 4.67 µm. Methane absorbs at 3.3 µm. N2O absorbs at 4.5 µm. A bandpass filter at the detector isolates each target wavelength. It passes only the relevant absorption band and rejects signals from other gases. Furthermore, dual-wavelength reference designs add a second detector at a non-absorbing wavelength. The ratio between sample and reference channels cancels source aging, temperature variation, and optical fouling. As a result, these sensors maintain calibration accuracy across 5 to 10 year service intervals without frequent recalibration.

OEM NDIR sensor modules integrate into fixed gas detectors, portable instruments, HVAC controllers, and process analyzers. The Senseair S8 covers 0 to 40,000 ppm CO2 from a compact 57×35×14mm housing at under 35mW power consumption. Industrial NDIR sensor heads deliver 4–20mA analog output and Modbus RTU communication for direct PLC and SCADA integration. Additionally, ATEX and IECEx certified NDIR sensor assemblies carry Zone 1 and Zone 2 hazardous area ratings — meeting the installation requirements of Pakistan’s oil and gas processing plants and petrochemical facilities.

Sensor service life reaches 5 to 10 years on professional NDIR designs. This significantly reduces replacement and maintenance costs compared to catalytic bead sensors in large multi-point detector installations.

These sensors serve Pakistan’s SSGC and SNGPL gas networks, OGDCL processing facilities in Sindh and Balochistan, WAPDA gas turbine stations, pharmaceutical cleanroom monitoring programs, hospital anaesthesia systems, and building HVAC automation installations across Karachi, Lahore, and Islamabad.

Tactical Supply Pakistan supplies NDIR gas sensors for industrial safety monitoring, HVAC control, process gas analysis, and environmental compliance procurement across Pakistan.