pF set A with ceramic plates

The equipment is suitable for determination of pF-curves in the range pF 2.0 - 4.2 (0.1 - 15 bar of suction). Futhermore the sets are suitable for the calibration of soil moisture blocks or soil moisture measurement equipment. The standard set contains amongst others: two extractors with ceramic plates (0.1 MPa, 0.3 MPa and 1.5 MPa, resp. 1, 3 and 15 bar) and accessories, soil sample rings, a pressure control panel and a compressor. Several ceramic plates with soil samples can be placed in the extractor at the same time. The pressure control panel is standard equiped with two manometers 0 - 2 MPa and 0- 0.4 MPa (resp. 0 - 20 bar and 0 - 4 bar). The included compressor (220V - 50 Hz) is specifically designed for this purpose: maximum pressure 2.0 MPa (20 bar), built-in safety precautions, completely guarded and quiet.

Benefits Set for pF-determination with ceramic plates

· Disturbed samples are saturated with water and placed on wet ceramic plate

· Pressure is put on samples and drained water is collected

· Collected quantity stands for suction (pF) value at the used pressure

· SA + SB both holds a 5 and 15 bar pan for 4 plates max each

· SA holds 4 pcs 1bar and 4pcs 15 bar plates

• 15 bar plates are very slow

· SB also holds 4 pcs 3 bar plates to speed up

Principle

Soil moisture is removed from the soil samples by raising air pressure in an extractor. A porous ceramic plate serves as a hydraulic link for water to move from the soil to the exterior of the extractor. The high pressure air will not flow through the pores in the plate since the pores are filled with water. The smaller the pore size, the higher pressure can be before air will pass through. During a run, at any set pressure in the extractor, soil moisture will flow around each of the soil particles and out through the ceramic plate and outflow tube. Equilibrium is reached when water flow from the outflow tube ceases. At equilibrium, there is an exact relationship between the air pressure in the extractor and the soil suction (and hence the moisture content) in the samples. Accuracy of equilibrium values will be no more accurate than the regulation of the air supply, therefore the pressure control panel has independent double regulators. Applications When knowing the soil moisture characteristics it is possible to determine/calculate:

• The pore volume of the soil.

· The pore size distribution of the soil.

• The capillary-rise capacity.

· The air and moisture contents of the soil with a given groundwater level.

· Determination of field capacity and available soil moisture.

· Soil suction research in relation to germination time of seeds. Advantages