Hygrometer Kalibrieren

And yeah, you may have gotten a bunk device.. or it's all within the wide range of error of a shitty device. just depends. cross-reference to figure out if tehy are accurate or not. get rid of anything operating outside it's stated +/- error rate.

Cheap hygrometers will be at mnimum +/- 5%. Cross reference reading with something known to be consistent. did a temperature change coincide this shift in RH? If so, it'll take the 2-way boveda packs an hour or two to mitigate a drop or rise in temperature. RH is relative, eh? So, if temps drop, absolute humidity stays teh same,which results in a rise in RH%. The boveda packs then slowly start to absorb that excess amount of moisture. (vice versa for a temp rising.. it will take time to release the moisture to mitigate it). I've been testing my 58% and 62% RH packs. As long as temps are consistent and i don't open them up, they are highly accurate. within 1-3% at all times and my hygrometer is +/- 3% error. Must always consider error of the intruments in use.

I've never calibrated my hygrometers, they're cheap enough to treat as disposable. I imagine they all carry a variance of +/- 2% or more. When you're talking about cheaper ones at least. If you spent money on something higher quality, I'd follow the manufacturer recommendations.