Dieletric Constant Rating

All dielectric constants are compared to air or vacuum, which is given a value of 1.0. The higher the constant number, the poorer the dielectric characteristics. A lower-quality PVC insulation may have a dielectric constant of 5.0 to 6.0 or higher. Polyethylene has a much better dielectric constant of approximately 2.0. Foamed polypropylene or polyethylene insulations have constants as low as 1.6.