Understanding the NDIR Sensor Module: How it Works and Applications

NDIR Sensor Module

We use NDIR(non-dispersive infrared) sensor module for gas detection and monitoring applications in various industries. These sensors rely on the principle of absorption of infrared radiation to measure the concentration of gases in the atmosphere. NDIR technology is highly reliable, accurate, and sensitive to low levels of gas concentrations. In this article, we will discuss in detail the working principle of NDIR sensor modules, their advantages, limitations, and their applications.

NDIR Sensor Module

Working Principle

The NDIR sensor module contains an IR source, an optical path that passes through a sample chamber, and an IR detector. The IR source emits a beam of infrared radiation that passes through the gas sample in the chamber. The specific wavelengths of the infrared radiation correspond to the absorption bands of the particular gas molecules being detected. The light that passes through the sample is then detected by the IR detector, which measures the amount of light absorbed by the gas molecules.

The amount of absorption is directly proportional to the concentration of the gas in the sample chamber. The detector converts the signal into an electrical output signal that can be further processed and displayed as the gas concentration measurement.

NDIR Sensor Module Applications

NDIR Sensor Module
  • Indoor air quality monitoring :NDIR sensor module in public buildings, offices, schools, hospitals, homes and other indoor air quality monitoring. These sensors can detect toxic gases, such as carbon dioxide, carbon monoxide and volatile organic compounds, which can cause health problems and seriously affect productivity.
  • Vehicle emission test: The NDIR sensor modules monitors vehicle emissions and measures the concentration of carbon dioxide, nitrogen oxides and hydrocarbons in vehicle exhaust. This helps ensure compliance with environmental regulations and improves vehicle fuel efficiency.
  • Industrial safety: In petroleum, manufacturing often see NDIR sensor modules to detect methane, hydrogen and ammonia and other harmful gases. This enables the company to take appropriate safety measures to prevent accidents.
  • Vending machines: Vending machines also use NDIR sensor modules to monitor carbon dioxide levels inside them. These sensors help maintain the freshness of the food and drinks being distributed.
  • Medical application: The NDIR gas sensor is required to detect the concentration of CO2 exhaled during anesthesia. This helps the anesthesiologist monitor the patient’s breathing rate and depth during surgery.

NDIR Sensor Module Advantages and Limitations


  • High accuracy even at low gas concentrations
  • Low maintenance requirements
  • Used for continuous monitoring due to their high sensitivity
  • Long lifespan
  • Wide detection range


  • Expensive compared to other gas detection technologies like electrochemical and catalytic sensors
  • Limited in their ability to detect certain gases
  • require frequent calibration


NDIR sensor modules are a highly sensitive, accurate, and reliable technology for gas detection and monitoring. While they are relatively expensive, their advantages make them ideal for many applications where precision measurements are required. By understanding their working principle and limitations, industries and individuals can select the suitable NDIR sensor modules for their specific needs.

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