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