Delta Education 160-4591 Sling Psychrometer Humidity Detector, Delta Education, Mfr#: 160-4591

Students swing the thermometers, with one wet and one dry bulb, and observe the difference in temperature on the two thermometers. Using a table, the difference in the temperatures determines the relative humidity. Instructions included. Features Sling Psychrometer Humidity Detector Specifications Country of Origin: United States Safety: Choking Hazard – Small Parts. Not for children under 3 yrs.