In order to check the accuracy of the automated system, three sets of
tests were conducted at different locationswith different soilmaterials.
For comparison purposes, at each test location, a manual and an automated
DRI testwere performed. In each location,we ran the automated
andmanual testswith enough of a separation distance to avoid interference
of thewet fronts. The DRI field experiments, as shown in Fig. 7, had
20 cm inner and 40 cm outer ring diameters with ring depths of 10 cm.
Themeasured steady state infiltration rates and initial infiltration values
for bothmethods were measured afterwards using the recorded results
of the flow. The values were compared for each set of tests. These data
are plotted in Table 2. The automatic test results showed no irregularity
in the infiltration from the pump response. After each experiment,
granulometric analyses were performed on the field soil samples
according to ASTM D 422-02 (ASTM, 2007).
The first testing location was the FSU Reservation area in Tallahassee,
Florida. The light brown sand of the test site could be described as
well-sorted, fine to coarse sand. It was categorized as SW based on
Unified, and A-3 in AASHTO soil classification systems. The test site
had a gently sloping surface (2–4°). A nearly constant infiltration rate
over the 40–60minute test runwas produced by relatively high permeability
of this soil. Graphs of cumulative infiltration rate versus time for
automated and manual tests performed in this location are provided in
Fig. 8. The second test locationwas in the vicinity of Tallahassee regional
airport area. The surface soil material included mottled dark and light
brown medium to fine sand that was classified as SP-SM based on
Unified and A-3 in AASHTO soil classification systems. The test site