NDIR Carbon Dioxide Sensor

NDIR carbon dioxide sensors measure CO₂ concentration by detecting infrared absorption at the gas’s characteristic 4.26 µm wavelength — delivering continuous, accurate, non-consumptive measurement across indoor air quality, HVAC control, greenhouse monitoring, industrial process gas, and clinical breath analysis applications without the drift and cross-sensitivity limitations of chemical CO₂ sensors.

The measurement cell directs broadband IR light from a source through the sample gas volume. A bandpass filter isolates the 4.26 µm absorption band before the photodetector. CO₂ molecules absorb IR energy at this wavelength and reduce transmitted intensity proportionally to concentration. The detector converts this signal reduction to a ppm or volume percent reading. Furthermore, dual-wavelength designs add a reference detector at a non-absorbing wavelength. The ratio between sample and reference channels cancels source intensity changes, temperature drift, and cell contamination — maintaining calibration accuracy over multi-year service intervals without frequent recalibration.

Miniaturized NDIR CO₂ modules such as the Senseair S8, Sensirion SCD40, and SCD41 measure 0 to 40,000 ppm CO₂ at ±40 ppm accuracy from compact housings consuming under 3.5mW in low-power mode. These integrate directly into HVAC demand-controlled ventilation systems, classroom and office air quality monitors, and building automation controllers. Additionally, industrial-grade NDIR analyzers cover 0 to 100% CO₂ volume for process gas purity verification, modified atmosphere packaging systems, fermentation vessel headspace monitoring, and biogas plant gas composition analysis.

Clinical capnography applications use fast-response mainstream NDIR CO₂ sensors with response times below 100 milliseconds — capturing the full exhaled CO₂ waveform during mechanical ventilation and spontaneous breathing in ICU and operating theatre monitoring. Sidestream capnography modules draw 50 to 200 ml/min sample flow through a desiccant-protected measurement cell — removing moisture from the breath sample before CO₂ measurement to prevent condensation errors.

These sensors serve Pakistan’s CMH and teaching hospital ventilator and capnography systems, commercial building HVAC demand ventilation installations across Karachi and Lahore, greenhouse cultivation facilities in Punjab, pharmaceutical fermentation process monitoring departments, and university environmental science research programs in Lahore and Karachi requiring accurate continuous CO₂ measurement across clinical, industrial, and environmental applications.

Tactical Supply Pakistan supplies NDIR carbon dioxide sensors for clinical capnography, HVAC control, industrial process monitoring, and environmental CO₂ measurement procurement across Pakistan.