ECOPROBE 5 - rs dynamics

ECOPROBE 5 provides a separate measurement for methane and displays sequences of measured values
on the screen, thereby providing important information about the potential of soils of differing permeabilities to
yield sufficient soil vapor. To illustrate this point, the graphs below were obtained using the same amount of
clay and sand soil samples, into which identical quantities of contaminant had been mixed (Figs. 4 and 5).
concentration
concentration
time
Fig. 4 -Sequence of measured values from a
clay soil sample with poor permeability . The
sharp decay of the curve indicates low
porosity of the soil.
Evaluated by ECOPROBE_VIEW software.
INTRODUCTION
In contrast to sand, clay yields soil vapor for a much shorter period of time.
time
Fig.6 – The difference between the
maximum concentration (long vertical
arrow) and the average concentration
(short vertical arrow).
clay sand
concentration
12
concentration
Fig. 5 - Sequence of measured values from a
sand soil sample with good permeability. The
“zero” decay of the curve indicates the high
porosity of the soil.
Evaluated by ECOPROBE_VIEW software
The integrated time concentration values measured for clay and sand, respectively, differ from the
maximum concentration obtained for each environment. Compare the cross hatched area and the vertical
arrow of each diagram (Figs.6 and 7).
ECOPROBE 5’s measuring cycle at a station varies usually from 20 to 30 seconds. During this interval
the software finds the highest measured value that indicates the maximum contaminant concentration in
the soil vapor.
Graphs showing sequences of measured values at a station can be stored on the instrument memory and
used for subsequent data interpretation.
time
clay sand
time
Fig.7 – The difference between the
maximum concentration (long vertical
arrow) and the average concentration
(short vertical arrow).