Air Permeability Apparatus

Air permeability apparatus is used to determine the maximum and minimum air permeability and the air resistance of the filter papers and other media. The apparatus has proved to be an important tool in the field of filtration technology and is widely used by manufacturers of filtration equipment.

The air permeability test is often carried out to evaluate and compare the breath-ability of various fabrics (coated and non-coated) for uses in applications, such as filtration element, raincoats and tents. The test helps evaluate the performance and effectiveness of industrial filter fabrics, parachutes, sail cloth, and the covering fabrics of pillows and covers.

Principle
The principle of the air permeability test is that air is absorbed through a particular area of fabric. The airflow rate is adjusted until a specified pressure difference between the two surfaces of fabric (face and back) is attained. After this the airflow is measured and the air permeability is calculated.

Components
Air permeability test equipment consists of :

• Clamping device to secure the test specimen in a flat tensionless state
• A device for preventing the air leakage from the edges of the test surface, generally called a guard ring
• An air pump, which is used to draw a steady flow of air through the clamped specimen
• A means of correcting the airflow rate to attain and hold the specified pressure drop from one side of the specimen to the other
• A pressure gauge or manometer for measuring the pressure drop from one side of the specimen to the other
• A flow meter for measuring the actual rate of air flow through the specimen

Air Permeability Test Apparatus for Powders:
The are some other microprocessor controlled technology based air permeability testers, which are used for the determination of the specific surface (Blaine value) of powders, such as cement. The tests are carried out as per the specified standards and once the test material is set inside the twin chambers, the automated test function records all the measurement in its database, which can be collected and analyzed later.

Design of these air permeability test equipment constitute a microprocessor control unit, a magnet valve and a membrane pump for measuring the cell testing apparatus. U-tube manometer featuring contact-less adjustable optical sensors, magnet valve and membrane pump creates vacuum for the functioning of the Blaine air permeability test.