Water detection in polymer dielectrics using photoacoustic spectroscopy

Abstract

Photoacoustic spectroscopy is used for the detection of sorbed water in two polymers used for their dielectric properties in electric cables: ethylene–propylene rubber and cross-linked polyethylene. The wavelength range is between 2 and 4 μm, where the OH-bond valence vibrations are observable. As the technique used distinguishes between surface and bulk absorption of the infrared beam, correlations have been made with relative humidity, and water content as measured by another technique, and with other studies of water-sorption processes in polymers.