Propagation Velocities of Dielectric Materials¶

Here are the approximate dielectric permittivities, electrical conductivities and radiowave velocities for various materials. Average velocity refers to a ballpark value for each material.

• Note that the electrical conductivity is in units milli-Siemens per meter

• Note that the velocity is in meters per nanosecond. To convert this to m/s, simply multiply by $$10^{-9}$$.

Material

Relative Permittivity

Conductivity (mS/m)

Average Velocity (m/ns)

Air

1

0

0.3

Fresh Water

80

0.5

0.033

Sea Water

80

3000

0.01

Ice

3-4

0.01

0.16

Dry Sand

3-5

0.01

0.15

Saturated Sand

20-30

0.1-1

0.06

Limestone

4-8

0.5-2

0.12

Shales

5-15

1-100

0.09

Silts

5-30

1-100

0.07

Clays

5-40

2-1000

0.06

Granite

4-6

0.01-1

0.13

Anhydrites

3-4

0.01-1

0.13