Common test methods for insulating and sheathing materials of electric and optical cables. Part 4-1. Methods specific to polyethylene and polypropylene compounds. Resistance to environmental stress cracking. Measurement of the melt flow index. Carbon black and/or mineral filler content measurement in polyethylene by direct combustion. Measurement of carbon black content by thermogravimetric analysis (TGA). Assessment of carbon black dispersion in polyethylene using a microscope
State system for ensuring the uniformity of measurements. Industrial application level gauges and float-type level gauges. Methods and means of calibration