A portable NDIR sensor for rapid detection of hydrogen cyanide in environment

Abstract

Cyanide pollution refers to the environmental pollution caused by cyanide and its compounds. As a derivative of cyanide, the leakage and excessive discharge of hydrogen cyanide will cause great harm to the surrounding animal and plant environment. Rapid detection of hydrogen cyanide can avoid some unnecessary environmental pollution. Based on the principle of non dispersive infrared(NDIR) detection, the infrared absorption of hydrogen cyanide at 3.0 μm and 14.3 μm was selected as the qualitative and quantitative basis. Two NDIR sensors were designed to detect 3.0 μm and 14.3 μm infrared absorption respectively after assembly. The standard curve between the concentration of hydrogen cyanide and the voltage response value was determined, and the performance of the two sensors was tested. Their detection ranges is 10ppm-3000ppm and 22ppm-3000ppm respectively. The maximum response time is less than 11s and RSD < 2%. After comparing the performance of the two sensors, the display values of the different sensors were processed. Finally, the two sensors were assembled into one sensor, the hydrogen cyanide concentration was displayed with one indication and different gases were mixed with hydrogen cyanide to pass into the gas chamber, which improved the anti-interference ability.