Gas -liquid discharge (bubble pressure method): apply pressure difference to the sides of the membrane, overcome the surface tension of the infiltration liquid in the membrane hole, and drive the infiltration fluid through the tunnel, obtain the pores of the pore throat of the membrane material according to this. At the same time, this method is also the standard method of ASTM thin film measurement.

Example: Take a certain membrane material as an example, the membrane is fully wet with the liquid that can be infiltrated with it. Due to the existence of the surface tension, the infiltration liquid will be bound in the pores of the membrane. The side of the membrane gradually increases the gas pressure. When the pressure of the surface tension of the infiltration liquid greater than the infiltration liquid in a pore diameter is reached, the infiltration liquid in the aperture will be introduced by the gas. Because the smaller the aperture, the higher the pressure of the surface tension, the higher the gas pressure required to launch the infiltration solution. Similarly, it can be seen that the infiltration liquid in the pores with the largest pore diameter will first be launched, causing the gas to pass through, and then as the pressure rises, the pore diameter is introduced from large to small, and the infiltration solution in the pores will be introduced in turn, causing the gas to via through the gases through , Until all the holes are opened, reaching the same rate as the dry membrane.

Liquid Drive Method: After infiltrating the filter material to be tested with the infiltration liquid that is completely infiltrated, the liquid that is insoluble with the infiltration liquid is used as the driver, and the infiltration liquid is driven out of the pores. Pressure data, obtain the pore data of the filter according to the Washburn formula. Because the interface tension of the liquid is far less than the qi liquid interface tension,

Therefore, compared to the gas solution driving method (bubble pressure method), the liquid driving method can test the smaller pore diameter filter material.

The relationship between the aperture and pressure is like Washburn formula:

D = 4 γcosθ/p

In the formula: d = pore diameter; γ = liquid surface tension; θ = contact angle; P = pressure difference

Percent of the flow distribution of the aperture:

F (d) = -d [fw/fd) x100]/dd

In the formula: FW = Wet sample traffic; FD = dry sample flow

GB/T 32361-2015 

Separate membrane aperture test method Bubble point and average flow method

ASTM D6767-02

Use the fawn tube to determine the feature method

ASTM F316-03

Test the test method of the hole size characteristics of the membrane filter through the foam point and average liquidity hole test

ASTM E1288-99

ASTM C-522

ASTM D-726

ASTM D-6539

Measuring the gas through the sample through the sample

ASTME1294-89 (1999)

Test method for testing the aperture characteristics of the film filter with automatic liquid perforated meter meter

BS 7591 -4 : 1993

The pore degree and pore size of the material. Part 4-Water Removal Evaluation Method

BS 3321-1986

Equivalent pore measurement method of fabric (bubble pressure test)

BS EN240003: 1993

Pilling sintering metal material. Testing of porosity in the porosity of the bubble test

HY/T 051-1999

Test method of hollow fiber microre filter membrane (in the compilation of membrane technical standards)

HY/T 064-2002

Tube ceramic micropores test method (in the compilation of film technology standards)

HY/T20061-2002

Hollow fiber micro filter membrane component

GB/T 14041.1-2007

Verification of the integrity of the hydraulic transmission filter element and the determination of the initial bubbling point

GB/T 24219-2009

Measurement of the woven filter cloth foaming point aperture

GB-T2679.14-1996

Measurement of the maximum pores of filter paper and cardboard

ISO 2942-2004

Hydraulic transmission-filter element-structural integrity test and first-bubble point measurement

DIN ISO 4003-1990

Sonalized sintering metal; determine the size of the aperture with a bubble test

DIN 58355-2-2005

Membrane filter. Part 2: Test of the Boom Point

JISK 3832-1900

Foaming point test method of membrane filter