Relative Permittivity

Overview

Engineering reference data for Relative Permittivity in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Temperature Dependence

The relative permittivity of a material is not a constant and can vary significantly with temperature. This is especially true for polar materials like water. For example, water's permittivity is approximately *88 at 0°C (32°F), dropping to *80 at 20°C (68°F) and further decreasing to *55.3 at 100°C (212°F). When selecting a dielectric material for an application, its permittivity value must be considered at the operating temperature.

References

• Original Source