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Porometer 3G™ Capillary Flow Porometry

The POROMETER 3G™ Series of instruments are the latest generation of capillary flow porometers. Using the technique known as liquid expulsion, they measure the Bubble Point, pore size distribution, permeability and other related information regarding the through pores in membranes and other filtration media. Developers and manufacturers of filter media around the world use these instruments to measure the bubble point and through pore size distribution of their track-etched membranes, woven or non-woven fabrics, hollow fibers, papers, or ceramics. They understand that these properties are crucial predictors of the materials ultimate filtration and separation performance.

The capillary flow porometry technique involves applying an increasing pressure to one side of a wetted porous sample while measuring the amount of flow downstream of the sample. At first this flow will be zero. Once the pressure is increased to the Bubble Point (associated with the largest through pore size present) an initial flow through the sample will be detected. As the pressure is increased, the pores in the sample are progressively emptied (largest through-pore first, then smaller ones). The flow rate through the emptied pores is recorded and used together with the pressure to provide information such as the maximum pore size, the mean flow pore size and full pore size distributions.

Because of the components used in the instruments of the POROMETER 3G Series of capillary flow porometers, they are useful for measuring the fluid permeability properties associated with the through pores as well as the bubble point and through pore size distributions present in a material.

Porometer 3G

3G Series Models

All Porometer 3G Series capillary flow porometers conform to ASTM standard methods D6767, E128, F316-03, and similar and offer the benefits of the pressure sense line and a compact design with the sample holder options external to the control module. The pressure sense line measures the actual pressure at the sample, eliminating the need to predict the pressure at the sample through the use of instrument calibrations and mathematical calculations. Having the sample holder external to the control module allows for measurement of a variety of sample configurations. The sample holders seen in the Accessory Holder flyer are available for all POROMETER 3G Series instruments. Depending upon the range of through pores present in your material one of the following models would be most appropriate for your needs.


  3G micro 3G z 3G zH
Pore size minimum 0.07 µm <0.03 µm <0.02 µm
Pore size maximum 100 µm 500 µm 0500 µm
Pressure controllers 1 2 2
Controller #1 0-100 psi 0-30 psi 0-30 psi
Controller #2 n/a 0-300 psi 0-500 psi
Pressure sensors 2 3 3
Sensor #1 0-5 psi
Sensor #2 0-100 psi
Sensor #3 n/a 0-250psi 0-500 psi
Flow sensors 1 1 or 2 2
sensors #1 0-100 L/min 0-100 L/min 0-10 L/min
sensors #2 n/a optional
0-200 L/min
0-200 L/min
Flow sensor switching n/a manual auto
  Technical Specifications
Pressure sensing accuracy +/- 0.05% f.s.
Pressure resolution: 16 bit A/D equivalent
Flow sensor type: Precision thermal mass flow
Flow sensor settling time: < 2 secs
Flow sensor temperature coeff.: <0.05%/oC (15-45oC)
  General Specifications
Mains power 90 - 240 Volts AC, 50/60 Hz
Main control unit dims.: 40cm(H) x 45cm(D) x 19cm(W)
Sample holder block dims.: 24cm(H) x 32 cm(D) x 15cm(W)
Table shows standard configurations. Different pressure and flow rate ranges are available for some models.