Home>Our businesses>Measuring Instruments>Measuring devices for electrochemistry/porous materials>Liquid Porometer

Measuring Instruments
Liquid Porometer


  • Hollow fibers (MF membranes, UF membranes)
  • Non-wovens
  • Papers
  • Battery separators


  • Bubble point pore diameter (maximum pore size)
  • Average pore diameter
  • Pore diameter distribution
  • Liquid permeability

Key features

  • Enables non-destructive testing without the use of mercury and liquid nitrogen
  • Enables extra-low pressure measurement using a fluid replacement method
  • Enables the measurement of the functioning parts of high-performance materials
  • Enables the measurement of membrares, cylinders, and hollow fibers
  • Computer-controlled automatic measurement


  • Pore size: 0.020〜5μm
  • Water/Methanol permeation rate: 0〜15cc/sec
  • Press compression pressure: 0〜200PSI
  • Software: windows-compliant/Japanese


A wetting liquid spontaneously fills the pores of the material. Two immiscible wetting liquids are selected. Liquid 1 with lower surface tension is used to fill the pores of the sample. Liquid 2 is added to the top of the sample and is pressurized to displace the first from the pores and flow through the empty pores. The flow rate of Liquid 2 is also measured without wetting the sample with Liquid 1. The pore diameter is related to the surface tension of the two liquids. The flow rates yield pore distribution and liquid permeability.

D = 4 γ1 cos θ1 / p


D = pore diameter
γ1 = Interfacial surface tension of liquids
cos θ1 = contact angle of liquid 1 on pore surface
p = differential pressure applied on the sample by liquid 2

Measuring Instruments

Products by application