NDIR CO2 Sensor

MH-Z19B NDIR CO2 Sensor Module Carbon Dioxide 0-5000ppm

MH-Z19B carbon dioxide gas sensor (hereinafter referred to as the sensor) is a general-purpose smart small-scale sensor that uses non-dispersive infrared (NDIR) principle to detect the presence of CO2 in the air, with good selectivity and anaerobic  Gas dependence, long life, and other characteristics; built-in temperature compensation; at the same time with serial output, analog output and PWM output, easy to use. The sensor is a high-performance sensor that combines mature infrared absorption gas detection technology with precise optical path design and sophisticated circuit design.

  1. Product model number: MH-Z19B
  2. Gas Detection: Carbon Dioxide
  3. Supply voltage: 4.5~5.5V DC
  4. Average current: <20mA (@5V power supply)
  5. Peak current: 150 mA (@5V supply)
  6. Interface level: 3.3V (5V compatible)
  7. Measurement range: 0~10000ppm can be selected within the range
  8. Output signal:
    • Serial (UART) (TTL level 3.3V)
    • PWM
    • Analog output (DAC) (default 0.4~2V) (0~3V range configurable)
  9. Warm-up time: 3min
  10. Response time: T90<120s
  11. Working temperature: 0 ~ 50°C
  12. Operating Humidity: 0 to 95% RH (non-condensing)
  13. Weight: 5g
  14. Life: >5 years


  • Vin: Power Positive (Vin)
  • GND: Negative Power Supply (GND)
  • Vo: Analog output
  • PWM: PWM
  • HD: HD (zero calibration, low for more than 7 seconds to calibrate)
  • Rx: UART (RXD) TTL Level Data Input
  • Tx: UART (TXD) TTL level data output
  • Pin 1: Analog Output Vo
  • Pin 2: None
  • Pin 3: Negative Power Supply (GND)
  • Pin 4: Positive Power Supply (Vin)
  • Pin 5: UART (RXD) TTL Level Data Input
  • Pin 6: UART (TXD) TTL Level Data Output
  • Pin 7: None