Propagation Velocities of Dielectric MaterialsΒΆ
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 |