GPR4 Concrete Scanner – User Manual
D-000002-000021
Earth Science Systems, LLC
February 29, 2019
Copyright © 2019 ESS, LLC. All rights reserved.
Page 13 of 28
usable range when interested in the more shallow portions of the surveyed range
(depth).
f.
Velocity of medium
The velocity of EM waves is dependent on the material type.
In order to properly convert from time of flight to depth, the velocity of the
medium must selected (see
Depth/Time units
above). Select the medium type
and the corresponding dielectric constant. The EM velocity is
ε
ν
/
c
=
where
v
is the EM wave velocity,
c
is the speed of light in a vacuum, and
ε
is the dielectric
constant of the medium.
Air
ε
= 1
Dry concrete/indoor/mature - Dry soil
ε
= 4
Damp concrete/outdoor - Damp soil
ε
= 6.5
Moist concrete/outdoor/young - Moist soil
ε
= 9
Wet concrete/outdoor/young - Wet soil
ε
= 16
Saturated concrete/outdoor - Saturated soil
ε
= 25
g.
Distance units
Select the units for the horizontal scale on the B-scan
(
Centimeters
,
Inches
,
Meters
,
Feet
,
Seconds
).
h.
Distance range
Select the horizontal range of the B-scan in distance units (
10
,
20
,
50
,
100
,
200
).
Figure 5. The plot configuration dialog.
