diff --git a/source/_components/sensor.mhz19.markdown b/source/_components/sensor.mhz19.markdown
index 027ada3ee2be..31ca4073856c 100644
--- a/source/_components/sensor.mhz19.markdown
+++ b/source/_components/sensor.mhz19.markdown
@@ -11,7 +11,7 @@ ha_category: sensor
 ha_release: 0.27
 ---
 
-The MH-Z19 is a small nondispersive infrared sensor that can measure CO2 sensors. High CO2 levels can lead to drowsiness, poor concentration, loss of attention or increased heart rate. Outside CO2 levels are usually between 250 and 350ppm, but inside levels can reach between 1000 and 5000 ppm. High CO2 levels indicate that you should increase ventilation.
+The MH-Z19 is a small nondispersive infrared sensor that can measure CO2 sensors. High CO2 levels can lead to drowsiness, poor concentration, loss of attention or increased heart rate. The CO2 level outside is around 400ppm, but inside levels can reach between 1000 and 5000 ppm. High CO2 levels indicate that you should increase ventilation.
 
 Check out the [Open Home Automation web site](https://www.open-homeautomation.com/2016/08/24/monitor-co2-levels-in-your-house/) for a quick guide how to connect the sensor to your PC or Raspberry Pi.