Filter media testing compares the material itself before pleating, bonding and framing. It helps manufacturers screen materials and shorten development cycles, but it does not replace testing of the finished filter. A media-efficiency table alone cannot determine a cleanroom class, final product life or leak-free performance.
Five results that matter
Five results that matter
- Fractional-efficiency curve: Shows how capture performance changes with particle size instead of reducing the result to one particle diameter.
- Pressure drop at face velocity: The same material can perform very differently at another face velocity, so the test condition must match the intended design.
- MPPS: HEPA et ULPA media should be evaluated near the most penetrating particle size. MPPS should not automatically be assumed to be 0.3 µm.
- Before-and-after conditioning: A high initial efficiency in charged synthetic media does not guarantee the same performance after the removable charge is reduced.
- Batch consistency: Fixed sampling locations and test conditions reveal meaningful variation in raw material, production process and supply batches.
Different applications need different emphasis
Different applications need different emphasis
For general-ventilation synthetic or electret media, compare initial performance, conditioned performance and pressure drop. For glass-fiber, PTFE and other high-efficiency media, MPPS, very low downstream concentration, instrument dynamic range and holder bypass become more important. Engine-intake and gas-turbine media can be screened as flat sheets, but dust capacity, resistance growth and sealing must still be verified on the complete element under the applicable finished-filter standard.
Why can good media still produce a poor filter?
Why can good media still produce a poor filter?
Pleat height and spacing change effective area and airflow distribution. Adhesive lines, frames and seals can introduce local leakage, while assembly stress may damage the media. Media testing therefore answers whether a material deserves to move into the next development stage. Finished-filter testing answers whether the final product meets its declared performance.
What should you check when choosing a media tester?
What should you check when choosing a media tester?
Define the target efficiency range, particle size or aerosol, sample area and face velocity first. Then evaluate upstream and downstream counting capability, dilution, holder sealing, répétabilité, calibration and data traceability. SCPUR SC-FT-1406D, SC-FT-1406DH et SC-FT-1406DU are configured for flat-sheet media across different efficiency ranges. They are not finished-filter test benches, and selection should start with the sample and test objective rather than the labels HEPA ou ULPA alone.
