Bubble point

The pressure at which air will pass through a wetted membrane filter. This pressure is correlated to the pore size of the membrane and thus this test can be used to confirm the pore size and integrity of a membrane or filter device.

FAQ
The pressure at which air will pass through a wetted membrane filter. This pressure is correlated to the pore size of the membrane and thus this test can be used to confirm the pore size and integrity of a membrane or filter device.
Bubble point test technique. A bubble point test is a technique that precedes to measure the needed pressure to apply the upstream side of a filter open pore of causing bulk through a wetted filter’s largest pores.
The bubble point pressure is the applied pressure at which a gas evacuates the liquid from a membrane pore. This pressure is specific to the liquid and membrane chemistry and its interaction.
The membrane filter is wetted completely with water (hydrophilic membranes) or isopropanol (hydrophobic membranes) and placed in an inline filter holder. Continuously increasing air pressure is applied to the inlet side until air bubbles appear at the outlet side. The bubble point correlates directly with the pore size and can be used to check the integrity of the filter.