Relationship between the diffusion time of ions in gelatin films and the absolute humidity in free air

Abstract

At a printing-works in Munich it was observed over a period of several years, in fully air-conditioned rooms, that the diffusion times of ions, penetrating a gelatin layer during the etching process of the printing cylinders, showed irregular fluctuations about the expected value within the range from −20% to +110%. Concurrent measurements of several meteorological parameters led to the detection of a strong linear relationship between the diffusion time of ions and the absolute humidity (AH-value) of the outside air. The AH-value seems to act as an indicator for part of the natural electromagnetic radiation affecting the properties of the gelatin film.