Long-time effects of humidity change on the dielectric properties of certain polymers

The study of the long-time effects of humidity change on the dielectric properties of dielectric materials was for the most part made on disk specimens from 2 to 5 mm thick which were cut down to a diameter of about 4 cm for measurement in micrometer electrode holders and on which evaporated metal (usually gold) electrodes were applied. Most of the results described in this paper were obtained on specimens of this type using a frequency of 1000 c/s at 23°C.