The temperature sensor works reasonably precise, here me is not negative noticed.
The hygrometer is very fast, but unfortunately only supplies in the lower area halfway reliable values. Compared to my old unit is noticeable in the range below 30% moisture both units vary only slightly (about 4% difference, according to display). From about 30%, the difference makes almost 10% difference, tendency with higher humidity rising to approximately 14% more compared to the old equipment.
That led me to make a control measurement under more controlled conditions (saline test, 75% humidity).
My old device showed after about 8 hours in a deviation of 1%, which differed by 14 TFA305011 from (89% instead of 75% rel. Humidity). It is clear to me that I should not expect too much precision in the price, but when the actual value can be estimated at best, and starting at 30% accounts for a difference of 10% indicated value, then mine is too vague. The 8-hour test was not carried out under laboratory conditions and can of course have a certain variance, but also so that would be the difference for me clearly. After another series devices with significantly better values were tested (about 3% deviation from the nominal), I suspect a defect here and will return the unit.
