Micrometre per Pascal Second (µm/(Pa·s))
The micrometre per pascal second is the SI unit of air permeance in the ISO 5636 series: the air flow through unit area of paper or board per unit pressure difference. Gurley, Bendtsen and Schopper readings all convert to it.
Symbol: µm/(Pa·s) (ASCII: um/(Pa s))
Quantity: air permeance (air flow per unit area per unit pressure difference)
SI relation: µm/(Pa·s) is the coherent SI unit of air permeance.
Derivation: Air permeance P = flow per unit area per unit pressure difference = 10⁻⁶ m/(Pa·s) (ISO 5636-1).
Exact: yes, by definition
Typical uses
- Paper and board air permeance (ISO 5636)
- Comparing Gurley, Bendtsen and Frazier results
- Sack paper, filter paper and separator specifications
Convert micrometres per pascal second to other units
| Conversion | 1 µm/(Pa·s) equals | Reverse |
|---|---|---|
| micrometre per pascal second to Gurley second | 127.0809506 s/100 mL | Gurley second to micrometre per pascal second |
| micrometre per pascal second to Frazier | 0.02460629921 cfm/ft² @125 Pa | Frazier to micrometre per pascal second |
| micrometre per pascal second to Bendtsen | 88.2 mL/min (Bendtsen) | Bendtsen to micrometre per pascal second |
| micrometre per pascal second to millimetre per second at 100 Pa | 0.1 mm/s @100 Pa | millimetre per second at 100 Pa to micrometre per pascal second |
| micrometre per pascal second to millimetre per second at 200 Pa | 0.2 mm/s @200 Pa | millimetre per second at 200 Pa to micrometre per pascal second |
Open the Gurley to Air Permeance Converter (Bendtsen, Frazier) to convert any value between all units.
Sources
- ISO 5636 Paper and board — Determination of air permeance (Part 3: Bendtsen method; Part 5: Gurley method), International Organization for Standardization , Part 1, definition of air permeance.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Micrometre per Pascal Second (µm/(Pa·s)). Retrieved October 29, 2026, from https://scientificconverters.com/units/micrometer-per-pascal-second/
IEEE
Scientific Converters, "Micrometre per Pascal Second (µm/(Pa·s))," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/units/micrometer-per-pascal-second/