Oakton WD-37250-00 Hygrometers – Measure Temperature: Yes, Style (Hygrometers): Fixed, Humidity Accuracy: ±3% from 10 to 90% RH; ±5% from 5 to 10% RH

Feature a human hair bundle humidity sensor and an aged bimetallic strip temperature sensor. Response time is 15 minutes for 45% of reading. Select 1-, 7-, or 32-day operation with the flip of a switch. A flashing LED indicates that the unit is operational. Uses two C batteries for up to 6 months of continuous operation. Test battery condition with the press of a button. The quartz-controlled drive mechanism consistently rotates chart drum even when batteries are weak.Exposure to RH levels above 90% can cause a decrease of about 7-10% RH in readings over the entire range due to temporary elongation of the hair bundle. When exposed to humidity levels below 80%, hair bundle will return to normal in about three weeks.