Review of non-dispersive infrared sensor technology

Non-Dispersive Infrared (NDIR) is an optical, non-contact, multi-component measurement technology that can be used for online monitoring of gas components and contaminants in liquids. It offers advantages such as good selectivity, strong anti-interference capability, long service life, and high accuracy. NDIR sensors are widely used in industrial, environmental, medical, food, and aviation fields. Based on the principle of gas absorption of specific wavelength infrared light, NDIR sensors provide long-term stability and resistance to environmental changes. This paper reviews the applications of NDIR sensors in monitoring gas concentrations and assessing oil conditions. Additionally, it summarizes the substances that NDIR sensors can monitor according to their absorption wavelengths and outlines the principles for selecting light sources in NDIR sensors.