Product review (1 stars): Inaccurate - bad buy
Very inaccurate. I have probably 12 gauges/meters throughout home and this one has stayed at RH at 43% even now in winter when it's very dry inside. All other meters range from 23-28 RH.
The also has dp at 47.3 (which correlates to temp of 70.5 and RH of 43).  It's just inaccurate - way off. Disappointing.
My Thomas Scientific traceable is at least within range with RH of 26.3 and dp of 34,5.  Still dry for comfort but at least accurate measure. Hope this helps. I wouldn't recommend the Allesun ETP110 meter to anyone who likes to keep track of indoor dew point and RH.