Samples taken today by Steve O&S:
To be expedient (and since not much structure in sandy soil), just took one sample 0-6cm.
At far, had to dig out core from the side and support from underneath to remove.
Despite almost 2 hours before weighing, saw no evidence of moisture condensed in container.
Site | Time | Weigh Time | Tare | "Wet" | Dry | Dry Density | Moisture (%mass) | Moisture (%vol) | EC5 reading (%vol) |
|---|---|---|---|---|---|---|---|---|---|
far | 11:20 | 13:10 | 3.1 | 176.7 | 172.2 | 1.23 | 2.7 | 3.3 | -1.2 |
near | 12:00 | 13:15 | 2.4 | 161.1 | 156.9 | 1.12 | 2.7 | 3.0 | 5.4 |
flr | 15:15 | 16:45 | 2.4 | 167.0 | 159.2 | 1.14 | 5.0 | 5.7 | -3.9 |
Treating the differences as a simple offset in the EC5 calibration, the Qsoil values for the entire project become somewhat believable.
We should contact Decagon to see if odd behavior in metallic soils would be expected...
P.S.(Mar 2014): During teardown, sensor depths were noted as 5, 3, 2 cm for near, far, flr, respectively, not just our usual 5cm at all sites. Since I only sampled 0–6 cm here, we can't look for any depth variation. However, we could expect that far and flr would read drier than near, as did occur. I don't know if 2 and 3cm are shallow enough to have suffered from lack-of-depth effects.