MH-Z19D CO2 Gas Sensor (hereinafter referred to as sensor) is a universal smart small sensor with two products: pins and terminals.
MH-Z19D uses the principle of non-dispersive infrared (NDIR) to detect CO2 in the air, which has the characteristics of good selectivity, no oxygen dependence and long life, and has serial port output and PWM output, which is convenient to use. The sensor is a high-performance sensor made by closely combining mature infrared absorption gas detection technology with precision optical path design and sophisticated circuit design.
Infrared carbon dioxide sensor is an optical sensor mainly composed of infrared light source, optical path, infrared detector, circuit and software algorithm.
Its working principle is based on the near-infrared spectroscopy of different gas molecules to select the absorption characteristics, and use the relationship between gas concentration and absorption intensity (Lambert-Beer law) to identify gas components and determine their concentration.
When measuring carbon dioxide concentration, the sensor has a spectral light source that emits infrared rays, and the light passes through the measured gas in the optical path, passes through the narrowband filter, and reaches the infrared detector.
Schematic diagram of single-channel infrared CO2 sensor
✅ Linear output, stable performance
✅ Anti-water vapor interference, no poisoning
✅ High sensitivity, low power consumption
✅ Long service life
Common ranges and accuracy
Air quality monitor