NDIR Gas Sensors and Detectors

NDIR gas sensors and detectors measure target gas concentration through infrared light absorption. They project IR light through a sample gas volume. The detector measures intensity reduction at the gas’s characteristic absorption wavelength. This principle is continuous, non-consumptive, and selective. Furthermore, it avoids the poisoning, drift, and cross-sensitivity issues that affect catalytic bead and electrochemical technologies.

Each gas absorbs IR radiation at a distinct 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. SO2 absorbs at 7.3 µm. Bandpass filters isolate each wavelength at the detector. They reject signals from all other atmospheric components. Additionally, dual-wavelength reference designs add a second detector at a non-absorbing wavelength. This ratio cancels source aging, temperature drift, and optical fouling. As a result, calibration accuracy holds across 5 to 10 year service intervals without frequent recalibration.

OEM sensor modules integrate into portable instruments, fixed detector heads, HVAC controllers, and process analyzers. They connect through 4–20mA, RS-232, Modbus RTU, and I2C interfaces. Compact units such as the Senseair S8 consume under 35mW — suitable for battery-powered IoT air quality devices. Industrial NDIR detector heads in ATEX and IECEx certified housings carry Zone 1 and Zone 2 hazardous area ratings. Moreover, open-path NDIR detector pairs project beams across 5 to 200 meters. They detect diffuse gas releases across large process areas with fewer mounting points than fixed-point arrays require.

Sensor service life reaches 5 to 10 years on professional designs. This reduces replacement frequency and maintenance costs significantly across large multi-point installations.

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

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