Whirling Hygrometer

The Ventilated Type Of Hygrometer Gives Greater Accuracy For Humidity Demonstrations And Is Particularly Useful For Measuring Local Differences In Humidity. There Are Two Thermometers Mounted Inside A Case, Fully Enclosed To Prevent Breakage, One Dry And Other Having A Wick Dipping Into A Water Reservoir At The End Of The Frame To Keep It Wet During Long Periods Of Non-Use. The Thermometers Are Stem Engraved With Lens Fronts For Easy Reading, Range -5 To 50 x 05°C. Includes Humidity And Temperature Conversion Chart. (Whirling Hygrometer)