Pressure Extractors are used in determining the water-holding characteristics of soil samples. Wetted soil samples are placed in the extractor, and a known pressure is applied, which forces the removal of any water held to the soil at a lower pressure. By analysing the sample at several different pressures, the characteristic pressure versus water content relationship can be determined for the soil.
A variety of extractors are available for analysing different sizes and quantities of samples, and for analysing samples in different pressure ranges. All Pressure Extractors require a source of regulated pressure for operation.
1600 5 BAR PRESSURE PLATE EXTRACTOR ONLY, 4 cell capacity
The Model 1600 Pressure Plate Extractor allows analysis of the water-holding characteristics of soil samples in the 0 to 5 bar pressure range. The pressure vessel is 9" (22 cm) deep and has an inside diameter of 12" (30 cm). Up to 4 ceramic plates can be accommodated at one time, allowing approximately 48 each 2-1/4" (5.7 cm) diameter samples to be analysed simultaneously. The Pressure Plate Extractor consists of a pressure vessel and lid, clamping bolts, O-ring seals,and outflow tube assemblies. The Pressure Plate Extractor can also be ordered with 4 one bar ceramic plates.
The Pressure Membrane Extractor uses a cellulose membrane supported on a screen drain plate. The Model 1600 Pressure Plate Extractor allows analysis of the water-holding characteristics of soil samples in the 0 to 5 bar pressure range. The pressure vessel is 9″ (22 cm) deep and has an inside diameter of 12″ (30 cm). Up to 4 ceramic plates can be accomodated at one time, allowing approximately 48 each 2-1/4″ (5.7 cm) diameter samples to be analysed simultaneously. The Pressure Plate Extractor consists of a pressure vessel and lid, clamping bolts, O-ring seals,and outflow tube assemblies. The Pressure Plate Extractor can also be ordered with 4 one bar ceramic plates.
A high-pressure hose and special high pressure manifold with regulator for connecting the extractor to a pressure source must be ordered separately. Cellulose membranes, soil sample retaining rings and an electrical lead-through are additional accessories that make the extractor complete for operation.
Height: 22 cm Diameter: 30 cm Weight: 20.40 kg
The 1600, 5 Bar Pressure Plate Extractor provides a sturdy, positive sealing pressure vessel that accepts the various Pressure Plate Cells available for work in the range of 0-5 Bars of soil suction, the primary growth range. The vessel is constructed of steel and has a working pressure of 75 PSI (5 Bars). All steel parts are plated for corrosion resistance and the inside surface of the vessel is coated with Neoprene. The Extractor will accept the 0675B1M3, 1 Bar Pressure Plate Cell; the 0675B03M1, 3 Bar Ceramic Plate Cell; and the 0675B05M1, 5 Bar Ceramic Plate Cell.
The 1 Bar Pressure Plate Cells are ideal for the routine determination of the 1/10 Bar and 1/3 Bar percentage in the cataloguing of soils as well as all other soil moisture equilibrium studies in the 0-1 Bar range of soil suction. The bubbling pressure of these cells is in excess of 1 Bar (14.5 PSI) and is usually between 18 and 25 PSI. These Cells also have the highest permeability of any of the Pressure Plate Cells, and therefore, provide the shortest possible time to reach equilibrium.
The, 0675B03M1, 3 Bar Pressure Plate Cells can be used for determination of the 1/10 Bar and 1/3 Bar percentages as well as soil moisture equilibrium studies in the extended range of 0-3 Bars of soil suction. Bubbling pressure of these Cells is in excess of 3 bars (43.5 PSI) and is usually between 55 and 65 PSI. The 0675B15M1, 15 Bar Pressure Plate Cells are not suitable for work in the 0-1 Bar range of soil suction due to their small pore size and relatively high permeability. However, they can be used effectively in this Extractor for soil moisture equilibrium studies in the 1-5 Bar range of soil suction. Bubbling pressure of these Cells is in excess of 15 Bars (220 PSI). For full range use, these Cells must be used in the 0675B15M1 15 Bar Pressure Plate Extractor.
The Various Pressure Plate Cells are not suitable for extracting solution from soils for chemical analysis. The immense surface area within the porous ceramic plate can cause disturbance and contamination of the soil solution. For extraction of the soil solution for chemical analysis, the 1000 Pressure Membrane Extractor must be used.
*Note; The “Bar” has become a standard unit for the expression of soil suction. By definition, a Bar is a unit of pressure equal to 106 dyne/cm2. This is equivalent to .987 atmospheres or 14.5 PSI.
|Pressure Extractors References|
|Azooz, R.H. and Arshad, M.A. 1995, ‘Tillage Effects on Thermal Conductivity of Two Soils in Northern British Columbia’, Soil Science Society of America Journal, vol. 59, pp. 1413-1423.
|Azooz, R.H., Arshad, M.A. and Franzluebbers, A.J. 1996, ‘Pore Size Distribution and Hydraulic Conductivity Affected by Tillage in Northwestern Canada’, Soil Science Society of America Journal, vol. 60, no. 4, pp. 1197-1201.
|Cresswell, H.P., Green, T.W. and McKenzie, N.J. 2008, ‘The Adequacy of Pressure Plate Apparatus for Determining Soil Water Retention’, Soil Science Society of America Journal, vol. 72, no. 1, pp. 41-49.
|Duniway, M.C., Herricka, J.E. and Monger, H.C. 2007, ‘The High Water-Holding Capacity of Petrocalcic Horizons’, Soil Science Society of America Journal, vol. 71, pp. 812-819.
|Fuentes, J.P., Flury, M. and Bezdicek, D.F. 2004, ‘Hydraulic Properties in a Silt Loam Soil under Natural Prairie, Conventional Till, and No-Till’, Soil Science Society of America Journal, vol. 68, pp. 1679–1688.
|Giakoumakis, S.G. and Tsakiris, G.P. 1999, ‘Quick Estimation of Hydraulic Conductivity in Unsaturated Sandy Loam Soil’, Irrigation and Drainage Systems, vol. 13, pp. 349-359.
|Katsura, S., Kosugi, K., Yamamoto, N. and Mizuyama, T. 2005, ‘Saturated and Unsaturated Hydraulic Conductivities and Water Retention Characteristics of Weathered Granitic Bedrock’, Vadose Zone Journal, vol. 5, pp. 35-47.
|Luedeling, E., Nagieb, M., Wichern, F., Brandt, M., Deurer, M. and Buerkert, A. 2005, ‘Drainage, Salt Leaching and Physico-chemical Properties of Irrigated Man-made Terrace Soils in a Mountain Oasis of Northern Oman’, Geoderma, vol. 125, pp. 273-285.
|Mecke, M., Westman, C.J. and Ilvesniemi, H. 2002, ‘Water Retention Capacity in Coarse Podzol Profiles Predicted from Measured Soil Properties’, Soil Science Society of America Journal, vol. 66, no. 1, pp. 1-11.
|Roels, S., Sermijn, J. and Carmeliet, J. 2002, Modelling Unsaturated Moisture Transport in Autoclaved Aerated Concrete: a Microstructural Approach, Building Physics 2002: 6th Nordic Symposium, Trondheim, Norway. 17-19 June pp. 167-174.
|Young, M.H., Albright, W., Pohlmann, K.F., Pohll, G., Zachritz, W.H., Zitzer, S., Shafer, D.S., Nester, I. and Oyelowo, L. 2006, ‘Incorporating Parametric Uncertainty in the Design of Alternative Landfill Covers in Arid Regions’, Vadose Zone Journal, vol. 5, pp. 742-750.