Convert Gurley Seconds to Micrometres per Pascal Second
Gurley Seconds and micrometres per pascal second are inversely related: µm/(Pa·s) = 127.0809506 ÷ s/100 mL, so 10 s/100 mL = 12.70809506 µm/(Pa·s).
Also searched as Gurley to µm/Pa·s, Gurley seconds to air permeance, Gurley porosity conversion and s/100 ml to um/pa s.
1 s/100 mL = 127.0809506 µm/(Pa·s)
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk Gurley second to micrometre per pascal second converter to paste a column from Excel.
How to Convert Gurley Second to Micrometre per Pascal Second
- µm/(Pa·s) = 127.0809506 ÷ s/100 mL
- s/100 mL = 127.0809506 ÷ µm/(Pa·s)
- Example: convert 10 s/100 mL to µm/(Pa·s): 127.0809506 ÷ 10 = 12.70809506 µm/(Pa·s)
Reference conditions. s/100 mL: 100 mL through 6.45 cm² (1 in²) at 1.22 kPa (TAPPI T 460, ISO 5636-5); assumes air flow proportional to pressure difference.
Formula
µm/(Pa·s) = 127.0809505655 ÷ s/100 mL
Derivation from SI units:
- Gurley t = seconds for 100 mL of air through 6.45 cm² at 1.22 kPa, so P = 100 mL ÷ (6.45 cm² × 1.22 kPa × t) ≈ 127.08 ÷ t µm/(Pa·s).
- Air permeance P = flow per unit area per unit pressure difference = 10⁻⁶ m/(Pa·s) (ISO 5636-1).
- Solving for µm/(Pa·s): µm/(Pa·s) = 127.0809505655 ÷ s/100 mL (a higher s/100 mL means a lower µm/(Pa·s))
One unit is a measured value, so the factor is approximate. Gurley Second definition: Gurley second; Micrometre per Pascal Second definition: micrometre per pascal second.
Worked examples
- A sack kraft of 10 s/100 mL has a permeance of 12.70809506 µm/(Pa·s).
127.0809506 ÷ 10 = 12.70809506 µm/(Pa·s) - A battery separator of 200 s/100 mL is 0.6354047528 µm/(Pa·s).
127.0809506 ÷ 200 = 0.6354047528 µm/(Pa·s)
Gurley Second to Micrometre per Pascal Second conversion table
| Gurley Seconds (s/100 mL) | Micrometres per Pascal Second (µm/(Pa·s)) |
|---|---|
| 1 s/100 mL | 127.0809506 µm/(Pa·s) |
| 5 s/100 mL | 25.41619011 µm/(Pa·s) |
| 10 s/100 mL | 12.70809506 µm/(Pa·s) |
| 20 s/100 mL | 6.354047528 µm/(Pa·s) |
| 30 s/100 mL | 4.236031686 µm/(Pa·s) |
| 50 s/100 mL | 2.541619011 µm/(Pa·s) |
| 100 s/100 mL | 1.270809506 µm/(Pa·s) |
| 200 s/100 mL | 0.6354047528 µm/(Pa·s) |
| 500 s/100 mL | 0.2541619011 µm/(Pa·s) |
| 1000 s/100 mL | 0.1270809506 µm/(Pa·s) |
Where it's used
Gurley air-resistance results from TAPPI T 460 and ISO 5636-5 testers are converted to air permeance in µm/(Pa·s), the SI unit of the ISO 5636 series. Divide 127.08 by the Gurley seconds.
Gurley Second to other air permeance units
| Conversion | 1 s/100 mL equals |
|---|---|
| Gurley second to micrometre per pascal second | 127.0809506 µm/(Pa·s) |
| Gurley second to Frazier | 3.126991894 cfm/ft² @125 Pa |
| Gurley second to Bendtsen | 11208.53984 mL/min (Bendtsen) |
| Gurley second to millimetre per second at 100 Pa | 12.70809506 mm/s @100 Pa |
| Gurley second to millimetre per second at 200 Pa | 25.41619011 mm/s @200 Pa |
Frequently asked questions
What is the formula from Gurley seconds to µm/(Pa·s)?
P = 127.08 ÷ t for the 100 mL cylinder: 100 mL through 6.45 cm² at 1.22 kPa. So 10 s = 12.70809506 µm/(Pa·s).
Why does a higher Gurley number mean lower permeance?
Gurley is a time: a denser sheet takes longer to pass 100 mL of air, so permeance is inversely proportional to the Gurley seconds.
What is the formula for Gurley seconds to micrometres per pascal second?
µm/(Pa·s) = 127.0809506 ÷ s/100 mL. The two systems are inversely related, so divide the constant by the value; do not multiply. For example, 127.0809506 ÷ 10 = 12.70809506 µm/(Pa·s).
Why does a higher s/100 mL give a lower µm/(Pa·s)?
Gurley Seconds counts length per unit mass (an indirect system), while micrometres per pascal second counts mass per unit length (a direct system). A finer yarn has a higher indirect number and a lower direct number.
Is the s/100 mL to µm/(Pa·s) conversion exact?
Not exactly. The Gurley second is a measured value (100 mL through 6.45 cm² (1 in²) at 1.22 kPa (TAPPI T 460, ISO 5636-5); assumes air flow proportional to pressure difference.). Results are good to about 5 significant figures.
Sources
- ISO 5636 Paper and board — Determination of air permeance (Part 3: Bendtsen method; Part 5: Gurley method), International Organization for Standardization , Part 5, Gurley method.
- TAPPI T 460 om-21 Air resistance of paper (Gurley method), TAPPI .
- 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). Convert Gurley Seconds to Micrometres per Pascal Second. Retrieved October 29, 2026, from https://scientificconverters.com/air-permeance/gurley-seconds-to-micrometers-per-pascal-second/
IEEE
Scientific Converters, "Convert Gurley Seconds to Micrometres per Pascal Second," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/air-permeance/gurley-seconds-to-micrometers-per-pascal-second/