What is a filter diffusion test?

What is a filter diffusion test?

Diffusion Test (also known as “forward flow”) A diffusion test applies a constant pressure of air on the upstream side of a filter saturated with liquid and measures the volume of air over time that diffuses through the filter. The liquid is usually water, and this test is usually used with the hydrophilic filters.

How do you test the integrity of a filter?

There are three primary nondestructive integrity test methods that can be used both before and after filtration:

1. Forward flow (diffusion) test.
2. Bubble point test.
3. Pressure hold test.

What is a filter bubble point test?

A bubble point test is a test designed to determine the pressure at which a continuous stream of bubbles is initially seen downstream of a wetted filter under gas pressure. Downstream of the filter, the pressure is lower. Therefore the gas in the water on the downstream side is driven out of solution.

Why is filter integrity test required?

Integrity testing sterilizing filters after a batch has been filtered can detect if the integrity of the filter has been compromised during the process. The stringent requirements of the pharmaceutical industry dictate that non-destructive filter integrity testing must be performed in each sterilizing application.

How do you test material integrity?

The Non-Destructive test (ND), performed with eddy current technology, is used to find surface faults (such as cracks, porosity, blow holes, inclusions, stripping, etc.) without changing the physical state of the part directly on the production line.

What is filter validation?

Filter validation is the process of confirming that the filter used to sterilize a pharmaceutical product does so adequately, by efficiently removing microorganisms. It is a critical step in the development and manufacturing of pharmaceuticals that use final filtration as the method for sterilization.

What type of integrity test is carried out on UFDF filter?

air–water diffusion test
The most common integrity test for UF membrane assemblies is the air–water diffusion test.

What is a diffusion test on a filter?

1. Diffusion Test (also known as “ forward flow ”) A diffusion test applies a constant pressure of air on the upstream side of a filter saturated with liquid and measures the volume of air over time that diffuses through the filter. The liquid is usually water, and this test is usually used with the hydrophilic filters.

What is the difference between integrity test and diffusion test?

During an integrity test, the bubble point test has to exceed the set minimum bubble point. Diffusion Test:- A completely wetted filter membrane provides a liquid layer across which, when a differential pressure is applied, the diffusive airflow occurs in accordance with Fick’s law of diffusion.

What is the diffused gas quantity of a gas filter?

The higher the pressure and the larger the filter surface, the larger is the diffused gas quantity. In case of the so-called forward flow test, the system replaces the gas quantity measured on the side of the filter continually by supplying the same gas quantity on the non-sterile side.

What is the difference between diffusion test and pressure decay test?

The pressure hold, forward flow, and pressure decay tests are variations of the diffusion test. The stringent requirements of the pharmaceutical industry dictate that non-destructive filter integrity testing must be performed in each sterilizing application.