Laboratory methods for determination of soil moisture retention potential (pF/WC) and hydraulic conductivity (k/psi)
Soil water conductivity and soil moisture retention potential are key parameters for the characterization of soils. Soil water transportation and water storage capability directly depend on these. To measure these parameters in correlation with the water tension and/or water content is a major task of a soil laboratory.
Table: Laboratory methods and their possible pF-ranges
Different laboratory methods for determination of soil moisture retention potentials (pF-curve) are available:
- the "Sand box" with range 0 ... -10 kPa (0,1 bar vacuum)
- the "Sand /Kaolin box” with range -10 ... -100 kPa
- the “Pressure plate extractors” with range 0 ... -1500 kPa
- the “WP4” with range -1000 kPa ... -300000 kPa
- or the “HYPROP” with range 0 ... -85 kPa (-250 kPa)
HYPROP
Starter set HYPROP-S
In cooperation with leading scientists UMS engineers have developed the HYPROP: a innovative, high-precision, modular System giving remarkably informative results about soil characteristics.
The soil parameters are measured simultaneously on several soil sampling rings. Factors out of the measuring range are modelized with fitting routines.
With HYPROP you now have a system on-hand to determine soil parameters from saturated to dry - with comparably low expenditure.
Product page: HYPROP
.
The soil parameters are measured simultaneously on several soil sampling rings. Factors out of the measuring range are modelized with fitting routines.
With HYPROP you now have a system on-hand to determine soil parameters from saturated to dry - with comparably low expenditure.
Product page: HYPROP
.
pF-laboratory equipment: Sand box method
Sand box pF 0 - 2
Sand or sand/kaolin boxes are good for pF-determination from pF 0 to 2 respectively pF 2 -to 2,7. Saturated soil samples are placed on a bed of saturated sand or kaolin clay to which a negative pressure is applied until the samples equalize with the tension and are weighed. The tension is subsequently increased until the dry weight of the samples are determined at the end.
pF- Laboratory equipment: pressure plate extractors
Laboratory set-up of pressure plate extractors
Pressure Plate Extractors are used to analyze the water-holding characteristics of soil samples in the range pF 2 to pF 4,2. Saturated soil samples are placed on a ceramic plate and put under a constant pressure. The sample weights corresponding to the different pressures are measured as well as the dry weight of the sample.
WP4 Potentiameter
WP4 Potentiameter
The WP4 measures the dewpoint temperature of air in equilibrium with a soil as well as the sample temperature to calculate sample water potentials as low as -300 MPa.
Contact
Georg von UnoldTel: +49 89 12 66 52 - 15
Fax: +49 89 12 66 52 - 20
E-Mail: gvu@ums-muc.de
Contact UMS
Contact Distributors
