Had initially only this hygrometer and therefore no reference values to a digital I had bought from the same company. The calibration using wet lobe that is specified in the description leads my to low values and is on the website of the manufacturer himself as "..not necessarily appropriate .." means. After alignment with the digital device at about 50% relative humidity, the values are not in the high range by over 10% (analog shows relatively higher values) and in the low range by up to 10% off (analog relative to low values), indicating might suggest -linear behavior of artificial hair. Maybe even a nonlinear scale as in a real hair hygrometer would therefore appropriate here. For the price in any case a bit disappointing. The thermometer on the other hand properly.