A New Form of a Dew-Point Hygrometer

Because of difficulties in securing consistent results with the Alluard form of dew-point hygrometer, a new form has been suggested. The important features of the new form are the small heat capacity of the dew forming surface, a polished concave surface in which the spot of dew forms and the application of a thermocouple to the measurement of the temperature at which the dew forms.