L&W Autoline Air Permeance | Automated measurement for paper and board

Why measure air permeance?

The measurement of air permeance is a useful control test for machine production. An air permeance test may be used as an indirect indicator of fluid permeance, as well as other variables such as: degree of refining, liquid absorbency and filtering efficiency for liquids or gases.

Air permeance is influenced by the internal structure and the surface finish of the paper. Internal structure is controlled largely by the type and length of fibers and their orientation; as well as the type and amount of fillers and sizing.

Accurate and reliable measurement

L&W Autoline Air Permeance

Based on the same measuring technology as the proven L&W Air Permeance Tester stand-alone testing equipment, L&W Autoline Air Permeance module uses the latest technology to measure air permeance in accordance with the most common measuring methods. With a measuring range covering 0.003–100 µm/Pas it is suitable for most paper grades. 

Why automated air permeance testing?

Traditional methods of measuring air permeance can be slow and laborious, but with L&W Autoline Air Permeance measuring is fast and automatic. The pre-set measuring time is usually 5 seconds for all types of samples, thereby saving considerable time when measuring paper grades with low levels of air permeance. Automatic measurements also minimize errors and poor reproducibility, which can be caused by differences in instrument handling. 


  • Measuring range covering 0.003–100 µm/Pas makes it suitable for most grades
  • Based on the proven L&W Air Permeance Tester 
  • Barometric pressure compensation
  • Bottom-side mechanism for precise parallelism 
  • Large measuring area 

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