pF suction plate module

Determination of soil moisture retention curves (soil water characteristic)

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Determination of pF curves with vacuum. Extension module for pF laboratory station and pF pressure step module, simultaneous use of different pressure steps

  • Up to 40 soil sample rings (100 cm³)
  • Extends sample capacity and pressure step spectrum
  • Includes sampling bottle with level adjustment
  • Precise adjustment of vacuum and drainage level
  • Optional: Module with sample saturation
Active filter area: 480 mm x 280 mm
Adjustable range: approx. 3 hPa (pF 0.5) to approx. 750 hPa (pF 2,9)
Number of sample ring kits: approx. 40 pieces with Ø 53 mm (100 cm³)
  approx. 30 pieces with Ø 60 mm (100 cm³)
  approx. 15 pieces with Ø 84 mm (250 cm³)
Frequently asked questions about "Soil water retention (pF) curves"

According to the Geological Survey of North Rhine-Westphalia in Krefeld, 3-4 working days are usually sufficient for dewatering of sample rings with a capacity of 100 ccm for samples of medium grain size and pressure levels up to 300 hPa. The equilibrium adjustment is delayed with

a) larger sample volume,
b) increased clay content and
c) higher pressure values

and can then take up to several weeks. At the Institute of Soil Science of the Christian-Albrechts-Universität Kiel, the following drainage periods are observed:

160 hPa 1-2 weeks
150 hPa 2-3 weeks
300 hPa 3-4 weeks
500 hPa 2-4 weeks

The total drainage period is between 10 and 13 weeks.
If you have any further questions about these specifications, we will be happy to put you in touch with the respective contact persons