Dome permeameter according to HARTGE

• Natural water movement occurs predominantly with very small pressure gradients. Currently, the water movement is described almost exclusively as a laminar flow with DARCY equation whereby the flux speed is proportionate to the effective pressure gradients. The usual kf measurements in soil science are conducted with comparatively high gradients which are rarely to be found in the natural water movement in soils. HARTGE therefore advocated the measurement with very small gradients. The Dome permeameter according to HARTGE meets these requirements. It serves to determine the kf value of the soil ring samples in the laboratory from the flux rate and the corresponding pressure difference whilst keeping the pressure gradients as small as possible. The saturated sample in the manual soil sample ring is placed in a tub on a filter plate and covered completely with water. A dome filled with water is placed over the soil sample ring beneath which a pressure gradient is generated over the sample height. This dome is suitable for the manual soil sample rings offered by UGT so that the soil sample can be inserted directly. In the test run, the water volume flowing through the sample during a specific measurement time is determined for the stationary flow. The area and length of the flow path are determined by the geometry of the soil sample ring. Depending on version, the pressure gradient is shown as height difference in the standpipes or recorded by a pressure sensor.

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  Advantages

  • Flux rate is recorded with verysmall gradients near to naturalwater movement
  • Flux rate may be adjusted to therespective soil sample
  • Testing of 10 manual soil samplerings with an inner volume 250cm³

  Set consisting of:

  • 1 sample tub with U-tube manometerand weighing table
  • 1 permeator dome with sealand tube connections

• Technical data

  • Resolution pressure differencewith standpipe:	1 mm water column
  • Resolution pressure differencepressure sensor:	0,1 mm water column