The Hygrometer is factory calibrated to 75% RH at 20°C. The calibration should remain stable for a minimum period one year from date of purchase unless the unit is physically damaged or misused.The measuringrange is 20% - 99%RH, with a temperature range of 0°C - 50°C / 32° - 122°F. Tolerances: +/- 3%, +/- 1°C / +/- 2°F. Replacement battery: CR2032.
