The Carbon Film Electric Hygrometer Element

Abstract

A new type of electric hygrometer, the “carbon film element” is described. Its response to humidity changes is by electronic rather than electrolytic conduction. Main features of the new element are: high sensitivity to moisture changes, rapid response, absence of polarization effect, and a calibration independent of temperature between 0° and 40° C. Components of the carbon film, performance data, and manufacturing techniques are described.