Torsion hygrometer
From Glossary of Meteorology
torsion hygrometer
A hygrometer in which the rotation of the hygrometric element is a function of the humidity.
Such hygrometers are constructed by taking a substance in which length is a function of the humidity and twisting or spiraling it under tension in such a manner that a change in length will cause a further rotation of the element.
See hygroscope.
See hygroscope.