NDIR Analyzer

NDIR analyzers measure gas concentration using infrared light absorption. They direct IR light through a sample cell and detect absorption at the target gas’s characteristic wavelength. This method is continuous, non-destructive, and highly selective. Furthermore, it does not consume the gas sample or degrade the sensor through chemical contact.

The measurement principle is straightforward. A broadband IR source sits at one end of an optical cell. A bandpass filter and photodetector sit at the other end. The filter passes only the specific wavelength absorbed by the target gas. CO₂ absorbs at 4.26 µm, CO at 4.67 µm, CH₄ at 3.3 µm, and N₂O at 4.5 µm. When target gas enters the cell, it absorbs IR energy and reduces detector signal. The analyzer converts this attenuation into a concentration reading. Additionally, dual-beam reference designs add a second optical path at an unaffected wavelength. This compensates for source drift, contamination, and temperature changes — maintaining calibration stability over multi-year service intervals.

Extractive analyzers draw samples through a conditioning system first. They remove moisture, particulates, and interfering compounds before measurement. This suits stack emissions monitoring at power plants, cement kilns, and industrial boilers. In-situ cross-stack analyzers mount on opposite sides of a flue duct. They project the IR beam across the full gas stream for representative measurement. Moreover, miniaturized OEM NDIR modules integrate CO₂ measurement into HVAC systems and building automation platforms at low power consumption.

Measurement ranges cover 0 to 100 ppm for trace gas monitoring up to 100% volume for pure gas stream analysis. Response times on fast-response models reach under 5 seconds.

These analyzers serve Pakistan’s oil and gas processing facilities in Sindh and Balochistan, power plant emissions monitoring programs, cement manufacturers in Hub and Karachi, hospital anaesthesia systems, and university environmental research departments in Lahore and Karachi.

Tactical Supply Pakistan supplies NDIR analyzers for industrial emissions monitoring, process gas analysis, and environmental compliance measurement procurement across Pakistan.