Humidity calibration accuracy

Hello,

I tried to calibrate humidity measurement following this topic https://blog.ruuvi.com/humidity-sensor-673c5b7636fc and the measurements I receive are around 69%, 70% and 69% and temperatures 23,7 - 23,9 C. I tried several different containers, with and without lids, different amount of salt and water, and still the humidity is always between 68 - 71% even after keeping the container unopened for several weeks. The real humidity should be 75%, so is the difference still within normal variations and within RuuviTag’s measurement accuracy and therefore safe to calibrate all tags to 75%, or should I calibrate them to a bit lower value?

Using iOS ruuvi app v. 0.5 (19), tags running in firmware 3.28.12

Thanks, Mikko

Hello,

It’s ok to calibrate the tags to 75 %. Please note that the calibration is on the app, so other devices will still read uncalibrated values.

Thanks Otso, will do so. I was thinking that something in my test setup was not ok, as the stated accuracy is -3… +3%, and these were +7 off.

Mikko