Measurement of crosslinking by-products in crosslinked polyethylene

摘要

At present, concentration of the crosslinking by-products crosslinked polyethylene used as insulation in high voltage cables is determined by a cumbersome, time consuming method involving taking a sample of the polymer, extracting volatile crosslinking by-products which affect the strength of the cable, and analyzing the by-products using a mass spectrometer. A novel method of in-situ measurement of the concentration of the crosslinking by-products in power cable insulation includes the step of detecting the thermo-luminescence emitted during the initial heating required to reduce the crosslinking by-products in the polymer prior to the electrical tests. Measurement of the intensity of thermoluminescence provides a direct indication of the by-product concentration which can be correlated to the electrical strength of the insulation.