The POROLIQ™ 1000 is a Liquid-Liquid Porometer (LLP). This rapid, precise method employed by the POROLIQ™ 1000 allows for testing of pore size down to 2nm and, compared to other techniques, uses lower pressures for characterisation of traditional micro-, nanoporous materials.


It is the first LLP equipment based on a pressure has driven concept, which guarantees the maximum accuracy, especially when measuring pore sizes in the submicron range.

A measurement consists first of complete saturation of the porous membrane with a wetting liquid. The subsequent displacement of the wetting liquid from the pores is achieved by a second, immiscible liquid (displacement liquid). The pressure (P) required to expel the wetting liquid out of the pore depends on its diameter (D) as expressed by the Young-Laplace equation P=4*γ*cos θ/D , where γ is the interfacial tension between the wetting and displacement liquid. Typical interfacial tension values lie between 0.35 and 4 mN/m. This allows pores as small as 2 nm to be probed or, in comparison to traditional gas liquid porometry, for the use of more moderate pressures to test traditional submicron pore size ranges.

By measuring the flow rate of liquid through the sample, a complete pore size distribution can be obtained.


  • Based on the pressure step/stability method: a data point is only recorded when the user-defined stability algorithms are met for both pressure and flow.
  • Detects the opening of a pore at a certain pressure and waits until all pores of the same diameter are completely opened before accepting a data point.
  • The POROLIQ™ 1000AQ uses a combination of three ultrasensitive liquid flow sensors to measure exactly and accurately flow rates from 0.16 μl/min (to detect the displacement of wetting liquid out of the pores from the very beginning).
  • Ideal for full characterization of hollow fibres at low pressures.

Paramteres Measured:

  • First Flow Point (FFP) size,flow and pressure
  • Pore size flow distribution
  • Mean Flow Pore (MFP) size and pressure
  • Total pore number
  • Smallest Pore Size (SP) pressure and number
  • Total pore area (% and μm²)
  • Mean Pore Diameter (MPD) and pressure
  • Liquid permeability
  • Cumulative flow distribution

Operating Software:

  • LabVIEW™ software for data acquisition and instrument control with an intuitive selection of all analysis parameters
  • Universally available PLC technology (National Instruments) with own runtime system
  • Easy export of results to Excel, Word and pdf file
  • Windows compatible
  • Advanced service menu facilitates diagnosis and service via Internet

Automatic switch between the pressure sensors and the flow meters during a measurement
− The best sensor is automatically selected to optimise the accuracy and resolution in the full pressure and flow range