VM 211 humidity Sensor (Earth Listener)

I have found that the reading of humidity is too high. 68% of the ads are displayed, of 2 other devices show 45% and 48%. How can I test or calibrate the sensor?
The remaining sensor values show realistic values.

I’m grateful for every tip

Hi @Firebird88,

We have tested the VMA342 AIR QUALITY SENSOR COMBO BOARD with various temperature sensors and humidity sensors in different environmental situations to calibrate them. We have seen a small offset for both values, they are manually fixed in the code.

The temperature is lowered with 3.3 degrees, the humidity is increased with 17 %. These values were calculated from our experiments, but can be modified in the code if your own findings are different from ours.

You can read this in our manual @ https://manuals.velleman.eu/article.php?id=1177 under chapter 3 “Compensation”.

And just to show you, we even tested this offset in crazy situations (see attached picture).


BTW, we do not recommend you put the EarthListener in the freezer, that is meant for glorious ice cream!

Kind regards,
VEL342