MH-Z19 0-5000PPM Infrared CO2 Sensor For CO2 Indoor Air Quality Monitor UART/PWM




The MH-Z19 is an indoor CO2 sensor. It is just a sensor, which means that you need to have separate system to read and control the data measured by the MH-Z19. This can for example be a wemos or nodemcu device that you need to have in place to control the MH-Z19 sensor. When you have this setup in place, you are able to send data from this sensor to your home automation or smart home platform.


1.High sensitivity, high resolution.
2.Output modes: UART and PWM wave.
3.Anti-water vapor interference.No poisoning.
4.Temperature compensation, excellent linear output.
5.Low power consumption,good stability and long lifespan.
6.It is widely used in the HVAC refrigeration and indoor air quality monitoring.

Specifications of the MH-Z19

Product Model: MH-Z19
Size(L*W*H):33 x 20 x 9 mm
Target Gas: CO2
Working voltage: 3.6 ~ 5.5 V DC
Average current: < 18 mA
Interface level: 3.3 V
Measuring range: 0 ~ 0.5% VOL optional
Output signal: UART / PWM
Preheat time: 3 min
Response Time: T90 < 60 s
Working temperature: 0 ~ 50°C
Working humidity: 0 ~ 95% RH (No condensation)
Lifespan: > 5 years

Use of the MH-Z19

The MH-Z19 has been developed by Winson Sensor as a sensor for professional climate installation solutions. And although the sensor is not in sold anymore by this company (but its successor is), the MH-Z19 is still sold via different webshops. Next to that, the sensor has been embraced by the DIY smart home community. There are many online places you can find discussions, specifications and tutorials on this sensor. For example revspace provides an overview of the commands and the mysensors forum has a topic with a teardown of the sensor. At, we are planning to add a tutorial on integrating the MH-Z19 in your smart home system as well.

DIY Air Quality measuring
  • Design
  • Quality
  • Usability
  • Home-Automation compatibility
  • Price


An affordable sensor that measures CO2 and temperature. Nice for a DIY air quality solution. Read our article how to make a indoor Air quality solution for Domoticz and Home Assistant.


  • small
  • well documented
  • accurate
  • affordable


  • you need to be a little handy
  • you need a charger
  • cost you some time and effort to make something cool.

You may also like…