NDIR Gas Sensor Technology Explained: How It Works and Why OEMs Prefer It

Your complete guide for engineers, product designers, and gas-detection OEMs

Non-Dispersive Infrared (NDIR) gas sensors have become the gold standard for gas detection in various industries, including HVAC, industrial safety, environmental monitoring, and biogas production. 

As OEMs develop compact, low-power, and high-accuracy devices, NDIR technology is increasingly preferred for detecting gases such as CO₂, hydrocarbons, refrigerants, and nitrous oxide (N₂O). 

This guide explains how NDIR sensors work, why they outperform other technologies, and how OEMs can integrate them into next-generation gas-detection systems. 

What Is NDIR Gas Sensing? 

NDIR sensing measures gas concentrations by analyzing the absorption of infrared (IR) light. 

Each gas absorbs IR light at a unique wavelength, creating a “fingerprint” for accurate identification. NDIR sensors detect the difference between emitted and received IR light to calculate gas concentration. 

In simple terms, IR light passes through the gas, the gas absorbs part of the light, a detector measures the remainder, and the concentration is determined. 

How an NDIR Sensor Works (Step by Step) 

1. Infrared Source

A miniature IR emitter produces a beam of infrared light. 

2. Sample Chamber

Gas flows into the sensing chamber for measurement. 

3. Optical Filter

Filters isolate the wavelength specific to the target gas. 

4. Infrared Detector

The detector measures the IR light passing through the gas. 

5. Signal Processing

A microprocessor converts the IR measurement into a gas concentration reading. 

Why OEMs Prefer NDIR Technology 

High Accuracy and Stability 

NDIR sensors are highly accurate because they rely on physical absorption, not chemical reactions. 

Long Sensor Life 

Non-consumptive sensing means 5+ years of operation with minimal drift. 

Excellent Selectivity 

Each gas has a unique IR absorption wavelength, minimising cross-gas interference. 

Low Maintenance 

Unlike catalytic bead or electrochemical sensors, NDIR sensors require little calibration or replacement. 

Resistant to Poisoning 

NDIR sensors are not affected by silicone, sulfur, or other chemical contaminants. 

Low Power Options 

Modern NDIR sensors support portable, battery-powered, and IoT devices. 

Wide Measurement Range 

Detect gases from low ppm levels to 100% volume concentration. 

Where NDIR Sensors Are Used 

• Industrial gas detection systems 

• HVAC and indoor air quality monitoring 

• Refrigerant leak detection 

• Biogas and landfill gas systems 

• Oil & gas safety monitoring 

• Environmental and emissions monitoring 

• Automotive and engine testing 

• Medical and life-science equipment 

NDIR vs Other Gas-Sensing Technologies 

Real-World Example 

Dynament NDIR sensors are widely used in biogas plants to monitor methane and CO₂, ensuring safety and compliance. Other customers integrate low-power CH₄ + CO₂ sensors into portable monitoring devices for HVAC and industrial safety applications. 

Why Dynament Leads the NDIR Sensor Market 

• High accuracy and ultra-fast response times 

• Certified flameproof sensors and housings 

• Low-power miniaturized sensors for portable and IoT devices 

• Dual-gas capabilities (e.g., CH₄ + CO₂) 

• Long service life with minimal calibration 

Conclusion 

NDIR gas sensors are the preferred choice for OEMs seeking reliable, long-lasting, and accurate gas detection. With applications in HVAC, industrial safety, environmental monitoring, and more, NDIR technology continues to set the benchmark for performance. 

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Contact our experts today ➜ for expert advice on integrating NDIR sensors into your gas detection system. 

View our full range of NDIR sensors for CO₂, hydrocarbons, refrigerants, and dual-gas applications.