Two-Speed, Spring-Wound Hygrothermograph
Use this hygrothermograph for indoor or sheltered outdoor use. The sturdy base, tinted cover, and carrying handle are constructed of lightweight, corrosion-resistant acrylic.
Hygrothermometer needs no external power or batteries—spring winding keeps the chart running for 8 days. Unit maintains a steady chart speed even when the motor begins to run down. Two easy-to-change gears are included; one for 1-day (26-hour) rotation and another for 7-day (172-hour) rotation.
Two-speed model 37250-10 is shown with optional axial fan 37250-50.