Soil moisture - TDR (HydroSense)

Parameter to be measured:

Soil moisture

Method:

TDR-method, display gives estimation of travle time in ms and water content after Topps (1980) equation

Equipment:

CAMPBELL: Two rod sensor CS620 with length of 120 mm and 200 mm and CD620 Hydrosense Display

Advantages:

easy and fast measurement of punctual soil moisture
manual measurements

Disadvantages:

Fractional digits of reflection time in ms: only one
Careful application of probe in stony soils
Accuracy: ±3% water content

What to watch out for:

Good contact between probe and medium has to be proved

Problems/Questions:

Price:

1100 € for probe, rods and reading device (1100)

Links

Other related web sites:

References

Petrone, RM Price, JS, Carey, SK, Waddington, JM 2004. Statistical characterization of the spatial variability of soil moisture in a cutover peatland. HYDROL PROCESS 18(1), 41-52.

Topp, GC, Davis, JL, Annan, AP, 1980. Electromagnetic Determination of Soil Water Content: Measurements in Coaxial Transmission Lines. WATER RESOURCES RESEARCH, 16(3), 574-582.

Wright, N, Quinton, WL, Hayashi, M 2008. Hillslope runoff from an ice-cored peat plateau in a discontinuous permafrost basin, Northwest Territories, Canada. HYDROL PROCESS 22(15), 2816-2828