There are four methods about this form.

1) specify base material and gas density to get dielectric constant 2) specify base material and dielectric constant to get gas density 3) specify gas dencity and dielectric constant to get base material's dielectric constant 4) specift base material to get graph of gas density and dielectric constantForce blank all un-needed parameters. The electronic parameters of PVC varies with it's components.

Formed insulation materials is used to reduce capacitance or to inclease characteristic impedance. The gas dencity is the ratio of volume of gas part for overall volume.

The relative dielectric constant is the ratio of dielectric constant of some material to dielectric constant of vacuum.